From cc1215d25b95487765967ed1f254a36931710c84 Mon Sep 17 00:00:00 2001
From: reeshika-h <reeshika.hosmani@contentstack.com>
Date: Wed, 27 May 2026 12:55:51 +0530
Subject: [PATCH 1/3] refactor: update exception handling in model tests to use
 ArgumentException

---
 ...entstack.Management.Core.Unit.Tests.csproj |  7 ----
 .../Models/DeliveryTokenTest.cs               | 12 +++----
 .../Models/PublishRuleTest.cs                 | 32 +++++++++----------
 .../Models/TaxonomyTest.cs                    | 26 +++++++--------
 .../Models/TermTest.cs                        | 24 +++++++-------
 .../Models/WebhookTest.cs                     | 24 +++++++-------
 .../Models/WorkflowTest.cs                    | 12 +++----
 .../Models/PublishRule.cs                     |  4 +--
 Contentstack.Management.Core/Models/Stack.cs  | 14 +++-----
 .../Models/Taxonomy.cs                        | 16 +++++-----
 Contentstack.Management.Core/Models/Term.cs   | 24 +++++++-------
 .../Models/Webhook.cs                         | 12 +++----
 .../Models/Workflow.cs                        | 16 +++++-----
 .../contentstack.management.core.csproj       | 12 +++----
 14 files changed, 111 insertions(+), 124 deletions(-)

diff --git a/Contentstack.Management.Core.Unit.Tests/Contentstack.Management.Core.Unit.Tests.csproj b/Contentstack.Management.Core.Unit.Tests/Contentstack.Management.Core.Unit.Tests.csproj
index fa0a3b9..f5284b1 100644
--- a/Contentstack.Management.Core.Unit.Tests/Contentstack.Management.Core.Unit.Tests.csproj
+++ b/Contentstack.Management.Core.Unit.Tests/Contentstack.Management.Core.Unit.Tests.csproj
@@ -60,19 +60,13 @@
 
     <Compile Remove="Models\AuditLogTest.cs" />
     <Compile Remove="Models\BaseModelTest.cs" />
-    <Compile Remove="Models\DeliveryTokenTest.cs" />
     <Compile Remove="Models\ExtensionTest.cs" />
     <Compile Remove="Models\ExtensionModelTest.cs" />
     <Compile Remove="Models\LabelTest.cs" />
     <Compile Remove="Models\PublishQueueTest.cs" />
-    <Compile Remove="Models\PublishRuleTest.cs" />
     <Compile Remove="Models\ReleaseTest.cs" />
     <Compile Remove="Models\ReleaseItemTest.cs" />
     <Compile Remove="Models\RoleTest.cs" />
-    <Compile Remove="Models\TaxonomyTest.cs" />
-    <Compile Remove="Models\TermTest.cs" />
-    <Compile Remove="Models\WebhookTest.cs" />
-    <Compile Remove="Models\WorkflowTest.cs" />
     <Compile Remove="Models\CustomExtensionTest.cs" />
 
     <!-- Bulk Operations excluded from migration scope -->
@@ -83,7 +77,6 @@
     <Compile Remove="Core\Services\Stack\BulkReleaseItemsServiceTest.cs" />
     <Compile Remove="Core\Services\Stack\BulkUnpublishServiceTest.cs" />
     <Compile Remove="Core\Services\Stack\BulkUpdateItemsServiceTest.cs" />
-    <Compile Remove="Core\Services\Stack\BulkWorkflowUpdateServiceTest.cs" />
     <Compile Remove="Services\BulkOperationServicesTest.cs" />
 
     <!-- OAuth tests (out of scope) -->
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/DeliveryTokenTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/DeliveryTokenTest.cs
index 88a36a9..a01124d 100644
--- a/Contentstack.Management.Core.Unit.Tests/Models/DeliveryTokenTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Models/DeliveryTokenTest.cs
@@ -32,12 +32,12 @@ public void Initialize_DeliveryToken()
             DeliveryToken token = new DeliveryToken(_stack);
             Assert.IsNull(token.Uid);
             Assert.AreEqual("stacks/delivery_tokens", token.resourcePath);
-            Assert.ThrowsException<InvalidOperationException>(() => token.Fetch());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => token.FetchAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => token.Update(_fixture.Create<DeliveryTokenModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => token.UpdateAsync(_fixture.Create<DeliveryTokenModel>()));
-            Assert.ThrowsException<InvalidOperationException>(() => token.Delete());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => token.DeleteAsync());
+            Assert.ThrowsException<ArgumentException>(() => token.Fetch());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => token.FetchAsync());
+            Assert.ThrowsException<ArgumentException>(() => token.Update(_fixture.Create<DeliveryTokenModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => token.UpdateAsync(_fixture.Create<DeliveryTokenModel>()));
+            Assert.ThrowsException<ArgumentException>(() => token.Delete());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => token.DeleteAsync());
             Assert.AreEqual(token.Query().GetType(), typeof(Query));
         }
 
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/PublishRuleTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/PublishRuleTest.cs
index 42d3790..6c83598 100644
--- a/Contentstack.Management.Core.Unit.Tests/Models/PublishRuleTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Models/PublishRuleTest.cs
@@ -29,12 +29,12 @@ public void Initialize_PublishRule()
 
             Assert.IsNull(publishRule.Uid);
             Assert.AreEqual($"/workflows/publishing_rules", publishRule.resourcePath);
-            Assert.ThrowsException<InvalidOperationException>(() => publishRule.Fetch());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => publishRule.FetchAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => publishRule.Update(_fixture.Create<PublishRuleModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => publishRule.UpdateAsync(_fixture.Create<PublishRuleModel>()));
-            Assert.ThrowsException<InvalidOperationException>(() => publishRule.Delete());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => publishRule.DeleteAsync());
+            Assert.ThrowsException<ArgumentException>(() => publishRule.Fetch());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => publishRule.FetchAsync());
+            Assert.ThrowsException<ArgumentException>(() => publishRule.Update(_fixture.Create<PublishRuleModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => publishRule.UpdateAsync(_fixture.Create<PublishRuleModel>()));
+            Assert.ThrowsException<ArgumentException>(() => publishRule.Delete());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => publishRule.DeleteAsync());
         }
 
         [TestMethod]
@@ -57,7 +57,7 @@ public void Should_Create_PublishRule()
             ContentstackResponse response = _stack.Workflow().PublishRule().Create(new PublishRuleModel());
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -66,7 +66,7 @@ public async System.Threading.Tasks.Task Should_Create_PublishRule_Async()
             ContentstackResponse response = await _stack.Workflow().PublishRule().CreateAsync(new PublishRuleModel());
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -75,7 +75,7 @@ public void Should_Find_All_PublishRule()
             ContentstackResponse response = _stack.Workflow().PublishRule().FindAll();
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -84,7 +84,7 @@ public async System.Threading.Tasks.Task Should_Find_All_PublishRule_Async()
             ContentstackResponse response = await _stack.Workflow().PublishRule().FindAllAsync();
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -93,7 +93,7 @@ public void Should_Fetch_PublishRule()
             ContentstackResponse response = _stack.Workflow().PublishRule(_fixture.Create<string>()).Fetch();
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -102,7 +102,7 @@ public async System.Threading.Tasks.Task Should_Find_PublishRule_Async()
             ContentstackResponse response = await _stack.Workflow().PublishRule(_fixture.Create<string>()).FetchAsync();
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -111,7 +111,7 @@ public void Should_Update_PublishRule()
             ContentstackResponse response = _stack.Workflow().PublishRule(_fixture.Create<string>()).Update(new PublishRuleModel());
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -120,7 +120,7 @@ public async System.Threading.Tasks.Task Should_Update_PublishRule_Async()
             ContentstackResponse response = await _stack.Workflow().PublishRule(_fixture.Create<string>()).UpdateAsync(new PublishRuleModel());
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -129,7 +129,7 @@ public void Should_Delete_PublishRule()
             ContentstackResponse response = _stack.Workflow().PublishRule(_fixture.Create<string>()).Delete();
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
 
         [TestMethod]
@@ -138,7 +138,7 @@ public async System.Threading.Tasks.Task Should_Delete_PublishRule_Async()
             ContentstackResponse response = await _stack.Workflow().PublishRule(_fixture.Create<string>()).DeleteAsync();
 
             Assert.AreEqual(_contentstackResponse.OpenResponse(), response.OpenResponse());
-            Assert.AreEqual(_contentstackResponse.OpenJObjectResponse().ToString(), response.OpenJObjectResponse().ToString());
+            Assert.AreEqual(_contentstackResponse.OpenJsonObjectResponse().ToString(), response.OpenJsonObjectResponse().ToString());
         }
     }
 }
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/TaxonomyTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/TaxonomyTest.cs
index 38ac5c9..66f7240 100644
--- a/Contentstack.Management.Core.Unit.Tests/Models/TaxonomyTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Models/TaxonomyTest.cs
@@ -33,13 +33,13 @@ public void Initialize_Taxonomy()
 
             Assert.IsNull(taxonomy.Uid);
             Assert.AreEqual("/taxonomies", taxonomy.resourcePath);
-            Assert.ThrowsException<InvalidOperationException>(() => taxonomy.Fetch());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => taxonomy.FetchAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => taxonomy.Update(_fixture.Create<TaxonomyModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => taxonomy.UpdateAsync(_fixture.Create<TaxonomyModel>()));
-            Assert.ThrowsException<InvalidOperationException>(() => taxonomy.Delete());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => taxonomy.DeleteAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => taxonomy.Terms());
+            Assert.ThrowsException<ArgumentException>(() => taxonomy.Fetch());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => taxonomy.FetchAsync());
+            Assert.ThrowsException<ArgumentException>(() => taxonomy.Update(_fixture.Create<TaxonomyModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => taxonomy.UpdateAsync(_fixture.Create<TaxonomyModel>()));
+            Assert.ThrowsException<ArgumentException>(() => taxonomy.Delete());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => taxonomy.DeleteAsync());
+            Assert.ThrowsException<ArgumentException>(() => taxonomy.Terms());
             Assert.AreEqual(typeof(Query), taxonomy.Query().GetType());
         }
 
@@ -136,22 +136,22 @@ public void Should_Get_Single_Term_From_Taxonomy()
         [TestMethod]
         public void Export_Throws_When_Uid_Is_Empty()
         {
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy().Export());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy().ExportAsync());
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy().Export());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy().ExportAsync());
         }
 
         [TestMethod]
         public void Locales_Throws_When_Uid_Is_Empty()
         {
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy().Locales());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy().LocalesAsync());
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy().Locales());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy().LocalesAsync());
         }
 
         [TestMethod]
         public void Localize_Throws_When_Uid_Is_Empty()
         {
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy().Localize(_fixture.Create<TaxonomyModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy().LocalizeAsync(_fixture.Create<TaxonomyModel>()));
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy().Localize(_fixture.Create<TaxonomyModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy().LocalizeAsync(_fixture.Create<TaxonomyModel>()));
         }
 
         [TestMethod]
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/TermTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/TermTest.cs
index 3267ab9..7191318 100644
--- a/Contentstack.Management.Core.Unit.Tests/Models/TermTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Models/TermTest.cs
@@ -32,8 +32,8 @@ public void Initialize_Term_Collection()
 
             Assert.IsNull(term.Uid);
             Assert.AreEqual($"/taxonomies/{taxonomyUid}/terms", term.resourcePath);
-            Assert.ThrowsException<InvalidOperationException>(() => term.Fetch());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => term.FetchAsync());
+            Assert.ThrowsException<ArgumentException>(() => term.Fetch());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => term.FetchAsync());
             Assert.AreEqual(typeof(Query), term.Query().GetType());
         }
 
@@ -139,40 +139,40 @@ public async System.Threading.Tasks.Task Should_Search_Terms_Async()
         public void Ancestors_Throws_When_Term_Uid_Is_Empty()
         {
             string taxonomyUid = _fixture.Create<string>();
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().Ancestors());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().AncestorsAsync());
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().Ancestors());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().AncestorsAsync());
         }
 
         [TestMethod]
         public void Descendants_Throws_When_Term_Uid_Is_Empty()
         {
             string taxonomyUid = _fixture.Create<string>();
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().Descendants());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().DescendantsAsync());
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().Descendants());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().DescendantsAsync());
         }
 
         [TestMethod]
         public void Move_Throws_When_Term_Uid_Is_Empty()
         {
             string taxonomyUid = _fixture.Create<string>();
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().Move(_fixture.Create<TermMoveModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().MoveAsync(_fixture.Create<TermMoveModel>()));
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().Move(_fixture.Create<TermMoveModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().MoveAsync(_fixture.Create<TermMoveModel>()));
         }
 
         [TestMethod]
         public void Locales_Throws_When_Term_Uid_Is_Empty()
         {
             string taxonomyUid = _fixture.Create<string>();
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().Locales());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().LocalesAsync());
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().Locales());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().LocalesAsync());
         }
 
         [TestMethod]
         public void Localize_Throws_When_Term_Uid_Is_Empty()
         {
             string taxonomyUid = _fixture.Create<string>();
-            Assert.ThrowsException<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().Localize(_fixture.Create<TermModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => _stack.Taxonomy(taxonomyUid).Terms().LocalizeAsync(_fixture.Create<TermModel>()));
+            Assert.ThrowsException<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().Localize(_fixture.Create<TermModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => _stack.Taxonomy(taxonomyUid).Terms().LocalizeAsync(_fixture.Create<TermModel>()));
         }
     }
 }
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/WebhookTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/WebhookTest.cs
index 2f5a905..1a85744 100644
--- a/Contentstack.Management.Core.Unit.Tests/Models/WebhookTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Models/WebhookTest.cs
@@ -30,18 +30,18 @@ public void Initialize_Webhook()
 
             Assert.IsNull(webhook.Uid);
             Assert.AreEqual($"/webhooks", webhook.resourcePath);
-            Assert.ThrowsException<InvalidOperationException>(() => webhook.Fetch());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => webhook.FetchAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => webhook.Update(_fixture.Create<WebhookModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => webhook.UpdateAsync(_fixture.Create<WebhookModel>()));
-            Assert.ThrowsException<InvalidOperationException>(() => webhook.Delete());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => webhook.DeleteAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => webhook.Executions());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => webhook.ExecutionsAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => webhook.Retry(_fixture.Create<string>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => webhook.RetryAsync(_fixture.Create<string>()));
-            Assert.ThrowsException<InvalidOperationException>(() => webhook.Logs(_fixture.Create<string>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => webhook.LogsAsync(_fixture.Create<string>()));
+            Assert.ThrowsException<ArgumentException>(() => webhook.Fetch());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => webhook.FetchAsync());
+            Assert.ThrowsException<ArgumentException>(() => webhook.Update(_fixture.Create<WebhookModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => webhook.UpdateAsync(_fixture.Create<WebhookModel>()));
+            Assert.ThrowsException<ArgumentException>(() => webhook.Delete());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => webhook.DeleteAsync());
+            Assert.ThrowsException<ArgumentException>(() => webhook.Executions());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => webhook.ExecutionsAsync());
+            Assert.ThrowsException<ArgumentException>(() => webhook.Retry(_fixture.Create<string>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => webhook.RetryAsync(_fixture.Create<string>()));
+            Assert.ThrowsException<ArgumentException>(() => webhook.Logs(_fixture.Create<string>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => webhook.LogsAsync(_fixture.Create<string>()));
             Assert.AreEqual(webhook.Query().GetType(), typeof(Query));
         }
 
diff --git a/Contentstack.Management.Core.Unit.Tests/Models/WorkflowTest.cs b/Contentstack.Management.Core.Unit.Tests/Models/WorkflowTest.cs
index eb4b312..d4daaf7 100644
--- a/Contentstack.Management.Core.Unit.Tests/Models/WorkflowTest.cs
+++ b/Contentstack.Management.Core.Unit.Tests/Models/WorkflowTest.cs
@@ -29,12 +29,12 @@ public void Initialize_Workflow()
 
             Assert.IsNull(workflow.Uid);
             Assert.AreEqual($"/workflows", workflow.resourcePath);
-            Assert.ThrowsException<InvalidOperationException>(() => workflow.Fetch());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => workflow.FetchAsync());
-            Assert.ThrowsException<InvalidOperationException>(() => workflow.Update(_fixture.Create<WorkflowModel>()));
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => workflow.UpdateAsync(_fixture.Create<WorkflowModel>()));
-            Assert.ThrowsException<InvalidOperationException>(() => workflow.Delete());
-            Assert.ThrowsExceptionAsync<InvalidOperationException>(() => workflow.DeleteAsync());
+            Assert.ThrowsException<ArgumentException>(() => workflow.Fetch());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => workflow.FetchAsync());
+            Assert.ThrowsException<ArgumentException>(() => workflow.Update(_fixture.Create<WorkflowModel>()));
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => workflow.UpdateAsync(_fixture.Create<WorkflowModel>()));
+            Assert.ThrowsException<ArgumentException>(() => workflow.Delete());
+            Assert.ThrowsExceptionAsync<ArgumentException>(() => workflow.DeleteAsync());
             Assert.AreEqual(workflow.PublishRule().GetType(), typeof(PublishRule));
         }
 
diff --git a/Contentstack.Management.Core/Models/PublishRule.cs b/Contentstack.Management.Core/Models/PublishRule.cs
index 60dabac..b1a7bf2 100644
--- a/Contentstack.Management.Core/Models/PublishRule.cs
+++ b/Contentstack.Management.Core/Models/PublishRule.cs
@@ -28,7 +28,7 @@ public virtual ContentstackResponse FindAll(ParameterCollection collection = nul
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, collection: collection);
+            var service = new FetchDeleteService(stack, resourcePath, collection: collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -48,7 +48,7 @@ public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection colle
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath, collection: collection);
+            var service = new FetchDeleteService(stack, resourcePath, collection: collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
diff --git a/Contentstack.Management.Core/Models/Stack.cs b/Contentstack.Management.Core/Models/Stack.cs
index 0142054..c0f0a5e 100644
--- a/Contentstack.Management.Core/Models/Stack.cs
+++ b/Contentstack.Management.Core/Models/Stack.cs
@@ -5,7 +5,7 @@
 using Contentstack.Management.Core.Services.Stack;
 using Contentstack.Management.Core.Utils;
 using Contentstack.Management.Core.Models;
-// using Contentstack.Management.Core.Models.Token; // Excluded for now
+using Contentstack.Management.Core.Models.Token;
 
 namespace Contentstack.Management.Core.Models
 {
@@ -667,7 +667,7 @@ public GlobalField GlobalField(string uid = null, string apiVersion = null)
 
         /*
         /// <summary>
-        /// <see cref="Models.Extension" /> let you create custom fields and custom widgets that lets you customize Contentstack's default UI and behavior. 
+        /// <see cref="Models.Extension" /> let you create custom fields and custom widgets that lets you customize Contentstack's default UI and behavior.
         /// </summary>
         /// <param name="uid">Optional, extension uid.</param>
         /// <example>
@@ -687,7 +687,7 @@ public Extension Extension(string uid = null)
         }
 
         /// <summary>
-        /// <see cref="Models.Label" /> allow you to group a collection of content within a stack. Using labels you can group content types that need to work together. 
+        /// <see cref="Models.Label" /> allow you to group a collection of content within a stack. Using labels you can group content types that need to work together.
         /// </summary>
         /// <param name="uid">Optional, label uid.</param>
         /// <example>
@@ -705,6 +705,7 @@ public Label Label(string uid = null)
 
             return new Label(this, uid);
         }
+        */
 
         /// <summary>
         /// <see cref="Models.Taxonomy" /> allows you to organize and categorize content using a hierarchical structure of terms.
@@ -726,7 +727,6 @@ public Taxonomy Taxonomy(string uid = null)
 
             return new Taxonomy(this, uid);
         }
-        */
 
         /// <summary>
         /// A publishing <see cref="Models.Environment" /> corresponds to one or more deployment servers or a content delivery destination where the entries need to be published.
@@ -748,7 +748,6 @@ public Environment Environment(string uid = null)
             return new Environment(this, uid);
         }
 
-        /*
         /// <summary>
         /// You can use <see cref="Models.Token.DeliveryToken" /> to authenticate Content Delivery API (CDA) requests and retrieve the published content of an environment.
         /// </summary>
@@ -788,7 +787,6 @@ public ManagementToken ManagementTokens(string uid = null)
 
             return new ManagementToken(this, uid);
         }
-        */
 
         /// <summary>
         /// A <see cref="Models.Role" /> collection of permissions that will be applicable to all the users who are assigned this role.
@@ -847,7 +845,6 @@ public Release Release(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Workflow" /></returns>
-        /*
         public Workflow Workflow(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -855,7 +852,6 @@ public Workflow Workflow(string uid = null)
 
             return new Workflow(this, uid);
         }
-        */
 
         /// <summary>
         /// A <see cref="Models.PublishQueue" /> displays the historical and current details of activities such as publish, unpublish, or delete that can be performed on entries and/or assets.
@@ -891,7 +887,6 @@ public PublishQueue PublishQueue(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.AuditLog" /></returns>
-        /*
         public Webhook Webhook(string uid = null)
         {
             ThrowIfNotLoggedIn();
@@ -899,7 +894,6 @@ public Webhook Webhook(string uid = null)
 
             return new Webhook(this, uid);
         }
-        */
 
         /// <summary>
         /// A <see cref="Models.AuditLog" /> displays a record of all the activities performed in a stack and helps you keep a track of all published items, updates, deletes, and current status of the existing content.
diff --git a/Contentstack.Management.Core/Models/Taxonomy.cs b/Contentstack.Management.Core/Models/Taxonomy.cs
index dbbaa01..3a22ea4 100644
--- a/Contentstack.Management.Core/Models/Taxonomy.cs
+++ b/Contentstack.Management.Core/Models/Taxonomy.cs
@@ -101,7 +101,7 @@ public ContentstackResponse Export(ParameterCollection collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/export", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/export", "GET", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -112,7 +112,7 @@ public Task<ContentstackResponse> ExportAsync(ParameterCollection collection = n
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/export", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/export", "GET", collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -123,7 +123,7 @@ public ContentstackResponse Locales(ParameterCollection collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/locales", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/locales", "GET", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -134,7 +134,7 @@ public Task<ContentstackResponse> LocalesAsync(ParameterCollection collection =
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/locales", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/locales", "GET", collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -145,7 +145,7 @@ public ContentstackResponse Localize(TaxonomyModel model, ParameterCollection co
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new CreateUpdateService<TaxonomyModel>(stack.client.serializer, stack, resourcePath, model, "taxonomy", "POST", collection);
+            var service = new CreateUpdateService<TaxonomyModel>(stack, resourcePath, model, "taxonomy", "POST", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -156,7 +156,7 @@ public Task<ContentstackResponse> LocalizeAsync(TaxonomyModel model, ParameterCo
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new CreateUpdateService<TaxonomyModel>(stack.client.serializer, stack, resourcePath, model, "taxonomy", "POST", collection);
+            var service = new CreateUpdateService<TaxonomyModel>(stack, resourcePath, model, "taxonomy", "POST", collection);
             return stack.client.InvokeAsync<CreateUpdateService<TaxonomyModel>, ContentstackResponse>(service);
         }
 
@@ -168,7 +168,7 @@ public ContentstackResponse Import(TaxonomyImportModel model, ParameterCollectio
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
             var path = resourcePath + "/import";
-            var service = new UploadService(stack.client.serializer, stack, path, model, "POST", collection);
+            var service = new UploadService(stack, path, model, "POST", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -180,7 +180,7 @@ public Task<ContentstackResponse> ImportAsync(TaxonomyImportModel model, Paramet
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
             var path = resourcePath + "/import";
-            var service = new UploadService(stack.client.serializer, stack, path, model, "POST", collection);
+            var service = new UploadService(stack, path, model, "POST", collection);
             return stack.client.InvokeAsync<UploadService, ContentstackResponse>(service);
         }
 
diff --git a/Contentstack.Management.Core/Models/Term.cs b/Contentstack.Management.Core/Models/Term.cs
index e48df74..473527d 100644
--- a/Contentstack.Management.Core/Models/Term.cs
+++ b/Contentstack.Management.Core/Models/Term.cs
@@ -101,7 +101,7 @@ public ContentstackResponse Ancestors(ParameterCollection collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/ancestors", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/ancestors", "GET", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -112,7 +112,7 @@ public Task<ContentstackResponse> AncestorsAsync(ParameterCollection collection
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/ancestors", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/ancestors", "GET", collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -123,7 +123,7 @@ public ContentstackResponse Descendants(ParameterCollection collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/descendants", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/descendants", "GET", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -134,7 +134,7 @@ public Task<ContentstackResponse> DescendantsAsync(ParameterCollection collectio
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/descendants", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/descendants", "GET", collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -145,7 +145,7 @@ public ContentstackResponse Move(TermMoveModel moveModel, ParameterCollection co
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new CreateUpdateService<TermMoveModel>(stack.client.serializer, stack, resourcePath + "/move", moveModel, "term", "PUT", collection);
+            var service = new CreateUpdateService<TermMoveModel>(stack, resourcePath + "/move", moveModel, "term", "PUT", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -156,7 +156,7 @@ public Task<ContentstackResponse> MoveAsync(TermMoveModel moveModel, ParameterCo
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new CreateUpdateService<TermMoveModel>(stack.client.serializer, stack, resourcePath + "/move", moveModel, "term", "PUT", collection);
+            var service = new CreateUpdateService<TermMoveModel>(stack, resourcePath + "/move", moveModel, "term", "PUT", collection);
             return stack.client.InvokeAsync<CreateUpdateService<TermMoveModel>, ContentstackResponse>(service);
         }
 
@@ -167,7 +167,7 @@ public ContentstackResponse Locales(ParameterCollection collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/locales", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/locales", "GET", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -178,7 +178,7 @@ public Task<ContentstackResponse> LocalesAsync(ParameterCollection collection =
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new FetchDeleteService(stack.client.serializer, stack, resourcePath + "/locales", "GET", collection);
+            var service = new FetchDeleteService(stack, resourcePath + "/locales", "GET", collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -189,7 +189,7 @@ public ContentstackResponse Localize(TermModel model, ParameterCollection collec
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new CreateUpdateService<TermModel>(stack.client.serializer, stack, resourcePath, model, "term", "POST", collection);
+            var service = new CreateUpdateService<TermModel>(stack, resourcePath, model, "term", "POST", collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -200,7 +200,7 @@ public Task<ContentstackResponse> LocalizeAsync(TermModel model, ParameterCollec
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
-            var service = new CreateUpdateService<TermModel>(stack.client.serializer, stack, resourcePath, model, "term", "POST", collection);
+            var service = new CreateUpdateService<TermModel>(stack, resourcePath, model, "term", "POST", collection);
             return stack.client.InvokeAsync<CreateUpdateService<TermModel>, ContentstackResponse>(service);
         }
 
@@ -215,7 +215,7 @@ public ContentstackResponse Search(string typeahead, ParameterCollection collect
             ThrowIfUidNotEmpty();
             var coll = collection ?? new ParameterCollection();
             coll.Add("typeahead", typeahead ?? string.Empty);
-            var service = new FetchDeleteService(stack.client.serializer, stack, "/taxonomies/$all/terms", "GET", coll);
+            var service = new FetchDeleteService(stack, "/taxonomies/$all/terms", "GET", coll);
             return stack.client.InvokeSync(service);
         }
 
@@ -228,7 +228,7 @@ public Task<ContentstackResponse> SearchAsync(string typeahead, ParameterCollect
             ThrowIfUidNotEmpty();
             var coll = collection ?? new ParameterCollection();
             coll.Add("typeahead", typeahead ?? string.Empty);
-            var service = new FetchDeleteService(stack.client.serializer, stack, "/taxonomies/$all/terms", "GET", coll);
+            var service = new FetchDeleteService(stack, "/taxonomies/$all/terms", "GET", coll);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
     }
diff --git a/Contentstack.Management.Core/Models/Webhook.cs b/Contentstack.Management.Core/Models/Webhook.cs
index 6c579ae..62eba2a 100644
--- a/Contentstack.Management.Core/Models/Webhook.cs
+++ b/Contentstack.Management.Core/Models/Webhook.cs
@@ -171,7 +171,7 @@ public ContentstackResponse Executions(ParameterCollection collection = null)
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, $"{resourcePath}/executions", collection: collection);
+            var service = new FetchDeleteService(stack, $"{resourcePath}/executions", collection: collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -190,7 +190,7 @@ public Task<ContentstackResponse> ExecutionsAsync(ParameterCollection collection
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, $"{resourcePath}/executions", collection: collection);
+            var service = new FetchDeleteService(stack, $"{resourcePath}/executions", collection: collection);
 
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
@@ -211,7 +211,7 @@ public ContentstackResponse Retry(string executionUid)
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, $"/webhooks/{executionUid}/retry", httpMethod: "POST");
+            var service = new FetchDeleteService(stack, $"/webhooks/{executionUid}/retry", httpMethod: "POST");
             return stack.client.InvokeSync(service);
         }
 
@@ -231,7 +231,7 @@ public Task<ContentstackResponse> RetryAsync(string executionUid)
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, $"/webhooks/{executionUid}/retry", httpMethod: "POST");
+            var service = new FetchDeleteService(stack, $"/webhooks/{executionUid}/retry", httpMethod: "POST");
 
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
@@ -252,7 +252,7 @@ public ContentstackResponse Logs(string executionUid)
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, $"/webhooks/{executionUid}/logs");
+            var service = new FetchDeleteService(stack, $"/webhooks/{executionUid}/logs");
             return stack.client.InvokeSync(service);
         }
 
@@ -272,7 +272,7 @@ public Task<ContentstackResponse> LogsAsync(string executionUid)
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack, $"/webhooks/{executionUid}/logs");
+            var service = new FetchDeleteService(stack, $"/webhooks/{executionUid}/logs");
 
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
diff --git a/Contentstack.Management.Core/Models/Workflow.cs b/Contentstack.Management.Core/Models/Workflow.cs
index 14a32d2..1871f61 100644
--- a/Contentstack.Management.Core/Models/Workflow.cs
+++ b/Contentstack.Management.Core/Models/Workflow.cs
@@ -30,7 +30,7 @@ public virtual ContentstackResponse FindAll(ParameterCollection collection = nul
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,resourcePath, collection: collection);
+            var service = new FetchDeleteService(stack,resourcePath, collection: collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -50,7 +50,7 @@ public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection colle
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,resourcePath, collection: collection);
+            var service = new FetchDeleteService(stack,resourcePath, collection: collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -197,7 +197,7 @@ public virtual ContentstackResponse Disable()
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,$"{resourcePath}/disable");
+            var service = new FetchDeleteService(stack,$"{resourcePath}/disable");
             return stack.client.InvokeSync(service);
         }
 
@@ -216,7 +216,7 @@ public virtual Task<ContentstackResponse> DisableAsync()
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,$"{resourcePath}/disable");
+            var service = new FetchDeleteService(stack,$"{resourcePath}/disable");
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -235,7 +235,7 @@ public virtual ContentstackResponse Enable()
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,$"{resourcePath}/enable");
+            var service = new FetchDeleteService(stack,$"{resourcePath}/enable");
             return stack.client.InvokeSync(service);
         }
 
@@ -254,7 +254,7 @@ public virtual Task<ContentstackResponse> EnableAsync()
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,$"{resourcePath}/enable");
+            var service = new FetchDeleteService(stack,$"{resourcePath}/enable");
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
 
@@ -292,7 +292,7 @@ public virtual ContentstackResponse GetPublishRule(string contentType, Parameter
                 throw new ArgumentNullException("contentType", CSConstants.ContentTypeRequired);
             }
 
-            var service = new FetchDeleteService(stack.client.serializer, stack,$"/workflows/content_type/{contentType}", collection: collection);
+            var service = new FetchDeleteService(stack,$"/workflows/content_type/{contentType}", collection: collection);
             return stack.client.InvokeSync(service);
         }
 
@@ -313,7 +313,7 @@ public virtual Task<ContentstackResponse> GetPublishRuleAsync(string contentType
             {
                 throw new ArgumentNullException("contentType", CSConstants.ContentTypeRequired);
             }
-            var service = new FetchDeleteService(stack.client.serializer, stack,$"/workflows/content_type/{contentType}", collection: collection);
+            var service = new FetchDeleteService(stack,$"/workflows/content_type/{contentType}", collection: collection);
             return stack.client.InvokeAsync<FetchDeleteService, ContentstackResponse>(service);
         }
     }
diff --git a/Contentstack.Management.Core/contentstack.management.core.csproj b/Contentstack.Management.Core/contentstack.management.core.csproj
index 8e04e7a..c4eba51 100644
--- a/Contentstack.Management.Core/contentstack.management.core.csproj
+++ b/Contentstack.Management.Core/contentstack.management.core.csproj
@@ -89,17 +89,17 @@
     <Compile Remove="Models\Locale.cs" />
     <!-- Organization.cs - RE-ENABLED -->
     <Compile Remove="Models\PublishQueue.cs" />
-    <Compile Remove="Models\PublishRule.cs" />
+
     <Compile Remove="Models\Release.cs" />
     <Compile Remove="Models\ReleaseItem.cs" />
     <Compile Remove="Models\Role.cs" />
-    <Compile Remove="Models\Taxonomy.cs" />
-    <Compile Remove="Models\Term.cs" />
+
+
     <!-- User.cs - RE-ENABLED -->
     <!-- Models\VariantGroup.cs - RE-ENABLED for VariantGroup module STJ migration -->
     <!-- Version.cs - RE-ENABLED for Assets module -->
-    <Compile Remove="Models\Webhook.cs" />
-    <Compile Remove="Models\Workflow.cs" />
+
+
     <Compile Remove="Models\CustomExtension\**\*.cs" />
     <!-- Re-enable core Field models for ContentType support -->
     <!-- Phase 1 field types - RE-ENABLED and converted to STJ -->
@@ -111,7 +111,7 @@
     <!-- Phase 4 field types - RE-ENABLED and converted to STJ -->
     <!-- GroupField.cs, ModularBlockField.cs (includes Block) - RE-ENABLED -->
     <!-- FieldMetadata.cs, Field.cs, FieldRules.cs - RE-ENABLED for ContentType -->
-    <Compile Remove="Models\Token\**\*.cs" />
+
     
     <!-- Re-enable core services for Client, User, Organization, Stack modules -->
     <Compile Remove="Services\DeleteReleaseItemService.cs" />

From 987b8afeb4e25484e29a4c3ce85552c087431794 Mon Sep 17 00:00:00 2001
From: reeshika-h <reeshika.hosmani@contentstack.com>
Date: Thu, 28 May 2026 11:45:50 +0530
Subject: [PATCH 2/3] refactor: update WorkflowTest assertions to use GetValue
 for JSON properties

---
 .../Contentstack.Management.Core.Tests.csproj                 | 3 ---
 .../IntegrationTest/Contentstack020_WorkflowTest.cs           | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/Contentstack.Management.Core.Tests/Contentstack.Management.Core.Tests.csproj b/Contentstack.Management.Core.Tests/Contentstack.Management.Core.Tests.csproj
index ad6ede9..ddf7b54 100644
--- a/Contentstack.Management.Core.Tests/Contentstack.Management.Core.Tests.csproj
+++ b/Contentstack.Management.Core.Tests/Contentstack.Management.Core.Tests.csproj
@@ -58,9 +58,6 @@
     <Compile Remove="IntegrationTest\Contentstack004_ReleaseTest.cs" />
     <Compile Remove="IntegrationTest\Contentstack012b_ContentTypeExpandedIntegrationTest.cs" />
 
-    <Compile Remove="IntegrationTest\Contentstack016_DeliveryTokenTest.cs" />
-    <Compile Remove="IntegrationTest\Contentstack017_TaxonomyTest.cs" />
     <Compile Remove="IntegrationTest\Contentstack019_RoleTest.cs" />
-    <Compile Remove="IntegrationTest\Contentstack020_WorkflowTest.cs" />
   </ItemGroup>
 </Project>
diff --git a/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack020_WorkflowTest.cs b/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack020_WorkflowTest.cs
index 79bd43d..5bd16fa 100644
--- a/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack020_WorkflowTest.cs
+++ b/Contentstack.Management.Core.Tests/IntegrationTest/Contentstack020_WorkflowTest.cs
@@ -1326,7 +1326,7 @@ public void Test005_Should_Update_Workflow_Properties()
                 AssertLogger.IsTrue(response.IsSuccessStatusCode, $"Workflow update failed with status {(int)response.StatusCode}", "workflowUpdateSuccess");
                 AssertLogger.IsNotNull(responseJson["workflow"], "workflowObject");
                 AssertLogger.AreEqual(updatedName, responseJson["workflow"]["name"]?.ToString(), "updatedWorkflowName");
-                AssertLogger.AreEqual(false, responseJson["workflow"]["enabled"]?.Value<bool>(), "updatedEnabledStatus");
+                AssertLogger.AreEqual(false, responseJson["workflow"]["enabled"]?.GetValue<bool>(), "updatedEnabledStatus");
                 
                 TestOutputLogger.LogContext("UpdatedWorkflowUid", workflowUid);
             }
@@ -1600,7 +1600,7 @@ public async Task Test012_Should_Update_Publish_Rule()
                 // Assert
                 AssertLogger.IsNotNull(response, "publishRuleUpdateResponse");
                 AssertLogger.IsTrue(response.IsSuccessStatusCode, $"Publish rule update failed with status {(int)response.StatusCode}", "publishRuleUpdateSuccess");
-                AssertLogger.AreEqual(true, responseJson["publishing_rule"]["disable_approver_publishing"]?.Value<bool>(), "updatedDisableApproval");
+                AssertLogger.AreEqual(true, responseJson["publishing_rule"]["disable_approver_publishing"]?.GetValue<bool>(), "updatedDisableApproval");
                 
                 TestOutputLogger.LogContext("UpdatedPublishRuleUid", publishRuleUid);
             }

From f05d48b1f2147a1cdea0d0dafd64b9e2b6ca358b Mon Sep 17 00:00:00 2001
From: reeshika-h <reeshika.hosmani@contentstack.com>
Date: Fri, 29 May 2026 12:56:13 +0530
Subject: [PATCH 3/3] refactor: update models to use nullable string parameters
 for uid and collection

---
 .../Models/PublishRule.cs                     | 22 +++++-----
 Contentstack.Management.Core/Models/Stack.cs  | 10 ++---
 .../Models/Taxonomy.cs                        | 36 ++++++++--------
 Contentstack.Management.Core/Models/Term.cs   | 42 +++++++++----------
 .../Models/Token/DeliveryToken.cs             | 18 ++++----
 .../Models/Token/ManagementToken.cs           | 18 ++++----
 .../Models/Webhook.cs                         | 22 +++++-----
 .../Models/Workflow.cs                        | 24 +++++------
 8 files changed, 96 insertions(+), 96 deletions(-)

diff --git a/Contentstack.Management.Core/Models/PublishRule.cs b/Contentstack.Management.Core/Models/PublishRule.cs
index b1a7bf2..3cbd0e9 100644
--- a/Contentstack.Management.Core/Models/PublishRule.cs
+++ b/Contentstack.Management.Core/Models/PublishRule.cs
@@ -6,7 +6,7 @@ namespace Contentstack.Management.Core.Models
 {
     public class PublishRule: BaseModel<PublishRuleModel>
     {
-        internal PublishRule(Stack stack, string uid)
+        internal PublishRule(Stack stack, string? uid)
             : base(stack, "publishing_rule", uid)
         {
             resourcePath = uid == null ? "/workflows/publishing_rules" : $"/workflows/publishing_rules/{uid}";
@@ -23,7 +23,7 @@ internal PublishRule(Stack stack, string uid)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public virtual ContentstackResponse FindAll(ParameterCollection collection = null)
+        public virtual ContentstackResponse FindAll(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -43,7 +43,7 @@ public virtual ContentstackResponse FindAll(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection collection = null)
+        public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -64,7 +64,7 @@ public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection colle
         /// </example>
         /// <param name="model">PublishRule Model for creating workflow.</param>
         /// <returns></returns>
-        public override ContentstackResponse Create(PublishRuleModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(PublishRuleModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -81,7 +81,7 @@ public override ContentstackResponse Create(PublishRuleModel model, ParameterCol
         /// </example>
         /// <param name="model">PublishRule Model for creating workflow.</param>
         /// <returns></returns>
-        public override Task<ContentstackResponse> CreateAsync(PublishRuleModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(PublishRuleModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -98,7 +98,7 @@ public override Task<ContentstackResponse> CreateAsync(PublishRuleModel model, P
         /// </example>
         /// <param name="model">PublishRule Model for updating Content Type.</param>
         /// <returns></returns>
-        public override ContentstackResponse Update(PublishRuleModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(PublishRuleModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -115,7 +115,7 @@ public override ContentstackResponse Update(PublishRuleModel model, ParameterCol
         /// </example>
         /// <param name="model">PublishRule Model for updating Content Type.</param>
         /// <returns></returns>
-        public override Task<ContentstackResponse> UpdateAsync(PublishRuleModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(PublishRuleModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -130,7 +130,7 @@ public override Task<ContentstackResponse> UpdateAsync(PublishRuleModel model, P
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -145,7 +145,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -160,7 +160,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -175,7 +175,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
diff --git a/Contentstack.Management.Core/Models/Stack.cs b/Contentstack.Management.Core/Models/Stack.cs
index e1c6e49..322ff9b 100644
--- a/Contentstack.Management.Core/Models/Stack.cs
+++ b/Contentstack.Management.Core/Models/Stack.cs
@@ -718,7 +718,7 @@ public Label Label(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Taxonomy" /></returns>
-        public Taxonomy Taxonomy(string uid = null)
+        public Taxonomy Taxonomy(string? uid = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
@@ -758,7 +758,7 @@ public Environment Environment(string? uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Token.DeliveryToken" /></returns>
-        public DeliveryToken DeliveryToken(string uid = null)
+        public DeliveryToken DeliveryToken(string? uid = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
@@ -778,7 +778,7 @@ public DeliveryToken DeliveryToken(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Token.ManagementToken" /></returns>
-        public ManagementToken ManagementTokens(string uid = null)
+        public ManagementToken ManagementTokens(string? uid = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
@@ -843,7 +843,7 @@ public Release Release(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.Workflow" /></returns>
-        public Workflow Workflow(string uid = null)
+        public Workflow Workflow(string? uid = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
@@ -885,7 +885,7 @@ public PublishQueue PublishQueue(string uid = null)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="Models.AuditLog" /></returns>
-        public Webhook Webhook(string uid = null)
+        public Webhook Webhook(string? uid = null)
         {
             ThrowIfNotLoggedIn();
             ThrowIfAPIKeyEmpty();
diff --git a/Contentstack.Management.Core/Models/Taxonomy.cs b/Contentstack.Management.Core/Models/Taxonomy.cs
index 3a22ea4..3614312 100644
--- a/Contentstack.Management.Core/Models/Taxonomy.cs
+++ b/Contentstack.Management.Core/Models/Taxonomy.cs
@@ -10,7 +10,7 @@ namespace Contentstack.Management.Core.Models
     /// </summary>
     public class Taxonomy : BaseModel<TaxonomyModel>
     {
-        internal Taxonomy(Stack stack, string uid = null)
+        internal Taxonomy(Stack stack, string? uid = null)
             : base(stack, "taxonomy", uid)
         {
             resourcePath = uid == null ? "/taxonomies" : $"/taxonomies/{uid}";
@@ -33,7 +33,7 @@ public Query Query()
         /// <summary>
         /// Create a taxonomy.
         /// </summary>
-        public override ContentstackResponse Create(TaxonomyModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(TaxonomyModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -41,7 +41,7 @@ public override ContentstackResponse Create(TaxonomyModel model, ParameterCollec
         /// <summary>
         /// Create a taxonomy asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> CreateAsync(TaxonomyModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(TaxonomyModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -49,7 +49,7 @@ public override Task<ContentstackResponse> CreateAsync(TaxonomyModel model, Para
         /// <summary>
         /// Update an existing taxonomy.
         /// </summary>
-        public override ContentstackResponse Update(TaxonomyModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(TaxonomyModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -57,7 +57,7 @@ public override ContentstackResponse Update(TaxonomyModel model, ParameterCollec
         /// <summary>
         /// Update an existing taxonomy asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> UpdateAsync(TaxonomyModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(TaxonomyModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -65,7 +65,7 @@ public override Task<ContentstackResponse> UpdateAsync(TaxonomyModel model, Para
         /// <summary>
         /// Fetch a single taxonomy.
         /// </summary>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -73,7 +73,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// <summary>
         /// Fetch a single taxonomy asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -81,7 +81,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// <summary>
         /// Delete a taxonomy.
         /// </summary>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -89,7 +89,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// <summary>
         /// Delete a taxonomy asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
@@ -97,7 +97,7 @@ public override Task<ContentstackResponse> DeleteAsync(ParameterCollection colle
         /// <summary>
         /// Export taxonomy. GET {resourcePath}/export with optional query parameters.
         /// </summary>
-        public ContentstackResponse Export(ParameterCollection collection = null)
+        public ContentstackResponse Export(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -108,7 +108,7 @@ public ContentstackResponse Export(ParameterCollection collection = null)
         /// <summary>
         /// Export taxonomy asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> ExportAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> ExportAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -119,7 +119,7 @@ public Task<ContentstackResponse> ExportAsync(ParameterCollection collection = n
         /// <summary>
         /// Get taxonomy locales. GET {resourcePath}/locales.
         /// </summary>
-        public ContentstackResponse Locales(ParameterCollection collection = null)
+        public ContentstackResponse Locales(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -130,7 +130,7 @@ public ContentstackResponse Locales(ParameterCollection collection = null)
         /// <summary>
         /// Get taxonomy locales asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> LocalesAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> LocalesAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -141,7 +141,7 @@ public Task<ContentstackResponse> LocalesAsync(ParameterCollection collection =
         /// <summary>
         /// Localize taxonomy. POST to resourcePath with body { taxonomy: model } and query params (e.g. locale).
         /// </summary>
-        public ContentstackResponse Localize(TaxonomyModel model, ParameterCollection collection = null)
+        public ContentstackResponse Localize(TaxonomyModel model, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -152,7 +152,7 @@ public ContentstackResponse Localize(TaxonomyModel model, ParameterCollection co
         /// <summary>
         /// Localize taxonomy asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> LocalizeAsync(TaxonomyModel model, ParameterCollection collection = null)
+        public Task<ContentstackResponse> LocalizeAsync(TaxonomyModel model, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -163,7 +163,7 @@ public Task<ContentstackResponse> LocalizeAsync(TaxonomyModel model, ParameterCo
         /// <summary>
         /// Import taxonomy. POST /taxonomies/import with multipart form (taxonomy file).
         /// </summary>
-        public ContentstackResponse Import(TaxonomyImportModel model, ParameterCollection collection = null)
+        public ContentstackResponse Import(TaxonomyImportModel model, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -175,7 +175,7 @@ public ContentstackResponse Import(TaxonomyImportModel model, ParameterCollectio
         /// <summary>
         /// Import taxonomy asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> ImportAsync(TaxonomyImportModel model, ParameterCollection collection = null)
+        public Task<ContentstackResponse> ImportAsync(TaxonomyImportModel model, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -194,7 +194,7 @@ public Task<ContentstackResponse> ImportAsync(TaxonomyImportModel model, Paramet
         /// stack.Taxonomy("taxonomy_uid").Terms("term_uid").Fetch();
         /// </code>
         /// </example>
-        public Term Terms(string termUid = null)
+        public Term Terms(string? termUid = null)
         {
             ThrowIfUidEmpty();
             return new Term(stack, Uid, termUid);
diff --git a/Contentstack.Management.Core/Models/Term.cs b/Contentstack.Management.Core/Models/Term.cs
index 473527d..4b00ecc 100644
--- a/Contentstack.Management.Core/Models/Term.cs
+++ b/Contentstack.Management.Core/Models/Term.cs
@@ -12,7 +12,7 @@ public class Term : BaseModel<TermModel>
     {
         private readonly string _taxonomyUid;
 
-        internal Term(Stack stack, string taxonomyUid, string termUid = null)
+        internal Term(Stack stack, string taxonomyUid, string? termUid = null)
             : base(stack, "term", termUid)
         {
             _taxonomyUid = taxonomyUid ?? throw new ArgumentNullException(nameof(taxonomyUid));
@@ -33,7 +33,7 @@ public Query Query()
         /// <summary>
         /// Create a term in this taxonomy.
         /// </summary>
-        public override ContentstackResponse Create(TermModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(TermModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -41,7 +41,7 @@ public override ContentstackResponse Create(TermModel model, ParameterCollection
         /// <summary>
         /// Create a term asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> CreateAsync(TermModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(TermModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -49,7 +49,7 @@ public override Task<ContentstackResponse> CreateAsync(TermModel model, Paramete
         /// <summary>
         /// Update an existing term.
         /// </summary>
-        public override ContentstackResponse Update(TermModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(TermModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -57,7 +57,7 @@ public override ContentstackResponse Update(TermModel model, ParameterCollection
         /// <summary>
         /// Update an existing term asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> UpdateAsync(TermModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(TermModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -65,7 +65,7 @@ public override Task<ContentstackResponse> UpdateAsync(TermModel model, Paramete
         /// <summary>
         /// Fetch a single term.
         /// </summary>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -73,7 +73,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// <summary>
         /// Fetch a single term asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -81,7 +81,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// <summary>
         /// Delete a term.
         /// </summary>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -89,7 +89,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// <summary>
         /// Delete a term asynchronously.
         /// </summary>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
@@ -97,7 +97,7 @@ public override Task<ContentstackResponse> DeleteAsync(ParameterCollection colle
         /// <summary>
         /// Get ancestor terms of this term. GET {resourcePath}/ancestors.
         /// </summary>
-        public ContentstackResponse Ancestors(ParameterCollection collection = null)
+        public ContentstackResponse Ancestors(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -108,7 +108,7 @@ public ContentstackResponse Ancestors(ParameterCollection collection = null)
         /// <summary>
         /// Get ancestor terms asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> AncestorsAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> AncestorsAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -119,7 +119,7 @@ public Task<ContentstackResponse> AncestorsAsync(ParameterCollection collection
         /// <summary>
         /// Get descendant terms of this term. GET {resourcePath}/descendants.
         /// </summary>
-        public ContentstackResponse Descendants(ParameterCollection collection = null)
+        public ContentstackResponse Descendants(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -130,7 +130,7 @@ public ContentstackResponse Descendants(ParameterCollection collection = null)
         /// <summary>
         /// Get descendant terms asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> DescendantsAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> DescendantsAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -141,7 +141,7 @@ public Task<ContentstackResponse> DescendantsAsync(ParameterCollection collectio
         /// <summary>
         /// Move term to a new parent and/or order. PUT {resourcePath}/move with body { term: moveModel }.
         /// </summary>
-        public ContentstackResponse Move(TermMoveModel moveModel, ParameterCollection collection = null)
+        public ContentstackResponse Move(TermMoveModel moveModel, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -152,7 +152,7 @@ public ContentstackResponse Move(TermMoveModel moveModel, ParameterCollection co
         /// <summary>
         /// Move term asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> MoveAsync(TermMoveModel moveModel, ParameterCollection collection = null)
+        public Task<ContentstackResponse> MoveAsync(TermMoveModel moveModel, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -163,7 +163,7 @@ public Task<ContentstackResponse> MoveAsync(TermMoveModel moveModel, ParameterCo
         /// <summary>
         /// Get term locales. GET {resourcePath}/locales.
         /// </summary>
-        public ContentstackResponse Locales(ParameterCollection collection = null)
+        public ContentstackResponse Locales(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -174,7 +174,7 @@ public ContentstackResponse Locales(ParameterCollection collection = null)
         /// <summary>
         /// Get term locales asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> LocalesAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> LocalesAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -185,7 +185,7 @@ public Task<ContentstackResponse> LocalesAsync(ParameterCollection collection =
         /// <summary>
         /// Localize term. POST to resourcePath with body { term: model } and query params (e.g. locale).
         /// </summary>
-        public ContentstackResponse Localize(TermModel model, ParameterCollection collection = null)
+        public ContentstackResponse Localize(TermModel model, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -196,7 +196,7 @@ public ContentstackResponse Localize(TermModel model, ParameterCollection collec
         /// <summary>
         /// Localize term asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> LocalizeAsync(TermModel model, ParameterCollection collection = null)
+        public Task<ContentstackResponse> LocalizeAsync(TermModel model, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -209,7 +209,7 @@ public Task<ContentstackResponse> LocalizeAsync(TermModel model, ParameterCollec
         /// </summary>
         /// <param name="typeahead">Search string for typeahead.</param>
         /// <param name="collection">Optional additional query parameters.</param>
-        public ContentstackResponse Search(string typeahead, ParameterCollection collection = null)
+        public ContentstackResponse Search(string typeahead, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -222,7 +222,7 @@ public ContentstackResponse Search(string typeahead, ParameterCollection collect
         /// <summary>
         /// Search terms across all taxonomies asynchronously.
         /// </summary>
-        public Task<ContentstackResponse> SearchAsync(string typeahead, ParameterCollection collection = null)
+        public Task<ContentstackResponse> SearchAsync(string typeahead, ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
diff --git a/Contentstack.Management.Core/Models/Token/DeliveryToken.cs b/Contentstack.Management.Core/Models/Token/DeliveryToken.cs
index 3840bb0..a7f7d4d 100644
--- a/Contentstack.Management.Core/Models/Token/DeliveryToken.cs
+++ b/Contentstack.Management.Core/Models/Token/DeliveryToken.cs
@@ -6,7 +6,7 @@ namespace Contentstack.Management.Core.Models.Token
 {
     public class DeliveryToken : BaseModel<DeliveryTokenModel>
     {
-        internal DeliveryToken(Stack stack, string uid = null)
+        internal DeliveryToken(Stack stack, string? uid = null)
            : base(stack, "token", uid)
         {
             resourcePath = uid == null ? "stacks/delivery_tokens" : $"stacks/delivery_tokens/{uid}";
@@ -40,7 +40,7 @@ public Query Query()
         /// </example>
         /// <param name="model">DeliveryToken Model for creating DeliveryToken.</param>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Create(DeliveryTokenModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(DeliveryTokenModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -57,7 +57,7 @@ public override ContentstackResponse Create(DeliveryTokenModel model, ParameterC
         /// </example>
         /// <param name="model">DeliveryToken Model for creating DeliveryToken.</param>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> CreateAsync(DeliveryTokenModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(DeliveryTokenModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -74,7 +74,7 @@ public override Task<ContentstackResponse> CreateAsync(DeliveryTokenModel model,
         /// </example>
         /// <param name="model">DeliveryToken Model for creating DeliveryToken.</param>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Update(DeliveryTokenModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(DeliveryTokenModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -91,7 +91,7 @@ public override ContentstackResponse Update(DeliveryTokenModel model, ParameterC
         /// </example>
         /// <param name="model">DeliveryToken Model for creating DeliveryToken.</param>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> UpdateAsync(DeliveryTokenModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(DeliveryTokenModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -106,7 +106,7 @@ public override Task<ContentstackResponse> UpdateAsync(DeliveryTokenModel model,
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -121,7 +121,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -136,7 +136,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -151,7 +151,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
diff --git a/Contentstack.Management.Core/Models/Token/ManagementToken.cs b/Contentstack.Management.Core/Models/Token/ManagementToken.cs
index f05a9b6..83f51b9 100644
--- a/Contentstack.Management.Core/Models/Token/ManagementToken.cs
+++ b/Contentstack.Management.Core/Models/Token/ManagementToken.cs
@@ -5,7 +5,7 @@ namespace Contentstack.Management.Core.Models.Token
 {
     public class ManagementToken : BaseModel<ManagementTokenModel>
     {
-        internal ManagementToken(Stack stack, string uid = null)
+        internal ManagementToken(Stack stack, string? uid = null)
           : base(stack, "token", uid)
         {
             resourcePath = uid == null ? "/delivery_tokens" : $"/delivery_tokens/{uid}";
@@ -40,7 +40,7 @@ public Query Query()
         /// </example>
         /// <param name="model">ManagementToken Model for creating ManagementToken.</param>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Create(ManagementTokenModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(ManagementTokenModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -58,7 +58,7 @@ public override ContentstackResponse Create(ManagementTokenModel model, Paramete
         /// </example>
         /// <param name="model">ManagementToken Model for creating ManagementToken.</param>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> CreateAsync(ManagementTokenModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(ManagementTokenModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -78,7 +78,7 @@ public override Task<ContentstackResponse> CreateAsync(ManagementTokenModel mode
         /// </example>
         /// <param name="model">ManagementToken Model for creating ManagementToken.</param>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Update(ManagementTokenModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(ManagementTokenModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -98,7 +98,7 @@ public override ContentstackResponse Update(ManagementTokenModel model, Paramete
         /// </example>
         /// <param name="model">ManagementToken Model for creating ManagementToken.</param>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> UpdateAsync(ManagementTokenModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(ManagementTokenModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -113,7 +113,7 @@ public override Task<ContentstackResponse> UpdateAsync(ManagementTokenModel mode
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -128,7 +128,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -143,7 +143,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -158,7 +158,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
diff --git a/Contentstack.Management.Core/Models/Webhook.cs b/Contentstack.Management.Core/Models/Webhook.cs
index 62eba2a..ba19425 100644
--- a/Contentstack.Management.Core/Models/Webhook.cs
+++ b/Contentstack.Management.Core/Models/Webhook.cs
@@ -6,7 +6,7 @@ namespace Contentstack.Management.Core.Models
 {
     public class Webhook : BaseModel<WebhookModel>
     {
-        internal Webhook(Stack stack, string uid = null)
+        internal Webhook(Stack stack, string? uid = null)
            : base(stack, "webhook", uid)
         {
             resourcePath = uid == null ? "/webhooks" : $"/webhooks/{uid}";
@@ -40,7 +40,7 @@ public Query Query()
         /// </example>
         /// <param name="model">Webhook Model for creating Webhook.</param>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Create(WebhookModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(WebhookModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -57,7 +57,7 @@ public override ContentstackResponse Create(WebhookModel model, ParameterCollect
         /// </example>
         /// <param name="model">Webhook Model for creating Webhook.</param>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> CreateAsync(WebhookModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(WebhookModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -74,7 +74,7 @@ public override Task<ContentstackResponse> CreateAsync(WebhookModel model, Param
         /// </example>
         /// <param name="model">Webhook Model for creating Webhook.</param>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Update(WebhookModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(WebhookModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -91,7 +91,7 @@ public override ContentstackResponse Update(WebhookModel model, ParameterCollect
         /// </example>
         /// <param name="model">Webhook Model for creating Webhook.</param>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> UpdateAsync(WebhookModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(WebhookModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -106,7 +106,7 @@ public override Task<ContentstackResponse> UpdateAsync(WebhookModel model, Param
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -121,7 +121,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -136,7 +136,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -151,7 +151,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
@@ -166,7 +166,7 @@ public override Task<ContentstackResponse> DeleteAsync(ParameterCollection colle
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public ContentstackResponse Executions(ParameterCollection collection = null)
+        public ContentstackResponse Executions(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
@@ -185,7 +185,7 @@ public ContentstackResponse Executions(ParameterCollection collection = null)
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public Task<ContentstackResponse> ExecutionsAsync(ParameterCollection collection = null)
+        public Task<ContentstackResponse> ExecutionsAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidEmpty();
diff --git a/Contentstack.Management.Core/Models/Workflow.cs b/Contentstack.Management.Core/Models/Workflow.cs
index 1871f61..4f18302 100644
--- a/Contentstack.Management.Core/Models/Workflow.cs
+++ b/Contentstack.Management.Core/Models/Workflow.cs
@@ -8,7 +8,7 @@ namespace Contentstack.Management.Core.Models
 {
     public class Workflow: BaseModel<WorkflowModel>
     {
-        internal Workflow(Stack stack, string uid)
+        internal Workflow(Stack stack, string? uid)
             : base(stack, "workflow", uid)
         {
             resourcePath = uid == null ? "/workflows" : $"/workflows/{uid}";
@@ -25,7 +25,7 @@ internal Workflow(Stack stack, string uid)
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public virtual ContentstackResponse FindAll(ParameterCollection collection = null)
+        public virtual ContentstackResponse FindAll(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -45,7 +45,7 @@ public virtual ContentstackResponse FindAll(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection collection = null)
+        public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection? collection = null)
         {
             stack.ThrowIfNotLoggedIn();
             ThrowIfUidNotEmpty();
@@ -66,7 +66,7 @@ public virtual Task<ContentstackResponse> FindAllAsync(ParameterCollection colle
         /// </example>
         /// <param name="model">Workflow Model for creating workflow.</param>
         /// <returns></returns>
-        public override ContentstackResponse Create(WorkflowModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Create(WorkflowModel model, ParameterCollection? collection = null)
         {
             return base.Create(model, collection);
         }
@@ -83,7 +83,7 @@ public override ContentstackResponse Create(WorkflowModel model, ParameterCollec
         /// </example>
         /// <param name="model">Workflow Model for creating workflow.</param>
         /// <returns></returns>
-        public override Task<ContentstackResponse> CreateAsync(WorkflowModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> CreateAsync(WorkflowModel model, ParameterCollection? collection = null)
         {
             return base.CreateAsync(model, collection);
         }
@@ -100,7 +100,7 @@ public override Task<ContentstackResponse> CreateAsync(WorkflowModel model, Para
         /// </example>
         /// <param name="model">Workflow Model for updating Content Type.</param>
         /// <returns></returns>
-        public override ContentstackResponse Update(WorkflowModel model, ParameterCollection collection = null)
+        public override ContentstackResponse Update(WorkflowModel model, ParameterCollection? collection = null)
         {
             return base.Update(model, collection);
         }
@@ -117,7 +117,7 @@ public override ContentstackResponse Update(WorkflowModel model, ParameterCollec
         /// </example>
         /// <param name="model">Workflow Model for updating Content Type.</param>
         /// <returns></returns>
-        public override Task<ContentstackResponse> UpdateAsync(WorkflowModel model, ParameterCollection collection = null)
+        public override Task<ContentstackResponse> UpdateAsync(WorkflowModel model, ParameterCollection? collection = null)
         {
             return base.UpdateAsync(model, collection);
         }
@@ -132,7 +132,7 @@ public override Task<ContentstackResponse> UpdateAsync(WorkflowModel model, Para
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Fetch(ParameterCollection collection = null)
+        public override ContentstackResponse Fetch(ParameterCollection? collection = null)
         {
             return base.Fetch(collection);
         }
@@ -147,7 +147,7 @@ public override ContentstackResponse Fetch(ParameterCollection collection = null
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> FetchAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> FetchAsync(ParameterCollection? collection = null)
         {
             return base.FetchAsync(collection);
         }
@@ -162,7 +162,7 @@ public override Task<ContentstackResponse> FetchAsync(ParameterCollection collec
         /// </code></pre>
         /// </example>
         /// <returns>The <see cref="ContentstackResponse"/>.</returns>
-        public override ContentstackResponse Delete(ParameterCollection collection = null)
+        public override ContentstackResponse Delete(ParameterCollection? collection = null)
         {
             return base.Delete(collection);
         }
@@ -177,7 +177,7 @@ public override ContentstackResponse Delete(ParameterCollection collection = nul
         /// </code></pre>
         /// </example>
         /// <returns>The Task.</returns>
-        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection collection = null)
+        public override Task<ContentstackResponse> DeleteAsync(ParameterCollection? collection = null)
         {
             return base.DeleteAsync(collection);
         }
@@ -269,7 +269,7 @@ public virtual Task<ContentstackResponse> EnableAsync()
         /// </example>
         /// <param name="uid">Optional Publish rule uid for performing rule specific operation</param>
         /// <returns></returns>
-        public PublishRule PublishRule(string uid = null)
+        public PublishRule PublishRule(string? uid = null)
         {
             return new PublishRule(stack, uid);
         }