diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java
index 73132481e383..d7c8debe9885 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java
@@ -606,6 +606,52 @@ protected CodegenDiscriminator createDiscriminator(String schemaName, Schema sch
     @Override
     public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> objs) {
         objs = super.postProcessAllModels(objs);
+
+        // For json_serializable, properly set up parent variables for inheritance
+        if (SERIALIZATION_LIBRARY_JSON_SERIALIZABLE.equals(library)) {
+            // Build a map of all models for quick lookup
+            Map<String, CodegenModel> allModelsMap = new HashMap<>();
+            for (ModelsMap modelsEntries : objs.values()) {
+                for (ModelMap modelsMap : modelsEntries.getModels()) {
+                    allModelsMap.put(modelsMap.getModel().getClassname(), modelsMap.getModel());
+                }
+            }
+
+            // Process models with inheritance
+            for (ModelsMap modelsEntries : objs.values()) {
+                for (ModelMap mo : modelsEntries.getModels()) {
+                    CodegenModel cm = mo.getModel();
+
+                    if (cm.getParent() != null && !cm.getParent().isEmpty()) {
+                        LOGGER.debug("Processing inheritance for model: {} (extends: {})", cm.getClassname(), cm.getParent());
+
+                        CodegenModel parentModel = allModelsMap.get(cm.getParent());
+
+                        if (parentModel != null && parentModel.getVars() != null && !parentModel.getVars().isEmpty()) {
+                            // Set parent variables
+                            cm.setParentVars(parentModel.getVars());
+
+                            // Remove parent properties from child's vars to avoid duplication
+                            Set<String> parentVarNames = cm.getParentVars().stream()
+                                    .map(CodegenProperty::getName)
+                                    .collect(Collectors.toSet());
+
+                            cm.setVars(cm.getVars().stream()
+                                    .filter(p -> !parentVarNames.contains(p.getName()))
+                                    .collect(Collectors.toList())
+                            );
+
+                            LOGGER.debug("Inheritance setup complete for {}: {} parent properties moved to parentVars",
+                                    cm.getClassname(), parentModel.getVars().size());
+                        } else {
+                            LOGGER.warn("Parent model '{}' not found or has no properties for child model '{}'",
+                                    cm.getParent(), cm.getClassname());
+                        }
+                    }
+                }
+            }
+        }
+
         if (SERIALIZATION_LIBRARY_BUILT_VALUE.equals(library)) {
             adaptToDartInheritance(objs);
             syncRootTypesWithInnerVars(objs);
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/class.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/class.mustache
index 73e37f9c373e..00dccb3ef856 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/class.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/class.mustache
@@ -32,7 +32,7 @@ part '{{classFilename}}.g.dart';
   disallowUnrecognizedKeys: false,
   explicitToJson: true,
 )
-class {{{classname}}} {
+class {{{classname}}}{{#parent}} extends {{{parent}}}{{/parent}} {
 {{>serialization/json_serializable/dart_constructor}}
 
 
@@ -89,14 +89,14 @@ class {{{classname}}} {
       runtimeType == other.runtimeType &&
       equals(
         [
-          {{#vars}}
+          {{#allVars}}
             {{{name}}},
-          {{/vars}}
+          {{/allVars}}
         ],
         [
-          {{#vars}}
+          {{#allVars}}
             other.{{{name}}},
-          {{/vars}}
+          {{/allVars}}
         ]
       );
     }
@@ -105,25 +105,26 @@ class {{{classname}}} {
   {{^useEquatable}}
     @override
     bool operator ==(Object other) => identical(this, other) || other is {{{classname}}} &&
-    {{#vars}}
+    runtimeType == other.runtimeType &&
+    {{#allVars}}
       other.{{{name}}} == {{{name}}}{{^-last}} &&{{/-last}}{{#-last}};{{/-last}}
-    {{/vars}}
+    {{/allVars}}
   {{/useEquatable}}
 
   {{#useEquatable}}
     @override
     int get hashCode => runtimeType.hashCode ^ mapPropsToHashCode([
-    {{#vars}}
+    {{#allVars}}
         {{{name}}},
-    {{/vars}}
+    {{/allVars}}
     ],);
   {{/useEquatable}}
   {{^useEquatable}}
     @override
     int get hashCode =>
-    {{#vars}}
+    {{#allVars}}
         {{#isNullable}}({{{name}}} == null ? 0 : {{{name}}}.hashCode){{/isNullable}}{{^isNullable}}{{{name}}}.hashCode{{/isNullable}}{{^-last}} +{{/-last}}{{#-last}};{{/-last}}
-    {{/vars}}
+    {{/allVars}}
   {{/useEquatable}}
 
   factory {{{classname}}}.fromJson(Map<String, dynamic> json) => _${{{classname}}}FromJson(json);
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/dart_constructor.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/dart_constructor.mustache
index b96c0d361835..4df75f1a79ba 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/dart_constructor.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/dart_constructor.mustache
@@ -1,11 +1,13 @@
-  /// Returns a new [{{{classname}}}] instance.
+/// Returns a new [{{{classname}}}] instance.
   {{{classname}}}({
-  {{#vars}}
-
+{{#vars}}
     {{!
         A field is required in Dart when it is
         required && !defaultValue in OAS
     }}
     {{^required}}{{#useOptional}}this.{{{name}}}{{#defaultValue}} = const Optional.present({{#isEnum}}{{^isContainer}}const {{{enumName}}}._({{/isContainer}}{{/isEnum}}{{{defaultValue}}}{{#isEnum}}{{^isContainer}}){{/isContainer}}{{/isEnum}}){{/defaultValue}}{{^defaultValue}} = const Optional.absent(){{/defaultValue}},{{/useOptional}}{{/required}}{{^required}}{{^useOptional}} this.{{{name}}}{{#defaultValue}} = {{#isEnum}}{{^isContainer}}const {{{enumName}}}._({{/isContainer}}{{/isEnum}}{{{defaultValue}}}{{#isEnum}}{{^isContainer}}){{/isContainer}}{{/isEnum}}{{/defaultValue}},{{/useOptional}}{{/required}}{{#required}}{{^defaultValue}}required {{/defaultValue}}{{/required}}{{#required}} this.{{{name}}}{{#defaultValue}} = {{#isEnum}}{{^isContainer}}const {{{enumName}}}._({{/isContainer}}{{/isEnum}}{{{defaultValue}}}{{#isEnum}}{{^isContainer}}){{/isContainer}}{{/isEnum}}{{/defaultValue}},{{/required}}
   {{/vars}}
+{{#parentVars}}
+    {{^required}}{{#useOptional}}super.{{{name}}}{{#defaultValue}} = const Optional.present({{#isEnum}}{{^isContainer}}const {{{enumName}}}._({{/isContainer}}{{/isEnum}}{{{defaultValue}}}{{#isEnum}}{{^isContainer}}){{/isContainer}}{{/isEnum}}){{/defaultValue}}{{^defaultValue}} = const Optional.absent(){{/defaultValue}},{{/useOptional}}{{/required}}{{^required}}{{^useOptional}} super.{{{name}}}{{#defaultValue}} = {{#isEnum}}{{^isContainer}}const {{{enumName}}}._({{/isContainer}}{{/isEnum}}{{{defaultValue}}}{{#isEnum}}{{^isContainer}}){{/isContainer}}{{/isEnum}}{{/defaultValue}},{{/useOptional}}{{/required}}{{#required}}{{^defaultValue}}required {{/defaultValue}}{{/required}}{{#required}} super.{{{name}}}{{#defaultValue}} = {{#isEnum}}{{^isContainer}}const {{{enumName}}}._({{/isContainer}}{{/isEnum}}{{{defaultValue}}}{{#isEnum}}{{^isContainer}}){{/isContainer}}{{/isEnum}}{{/defaultValue}},{{/required}}
+  {{/parentVars}}
   });
\ No newline at end of file
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Cat.md b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Cat.md
index 6552eea4b435..c1c078d2b65e 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Cat.md
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Cat.md
@@ -8,8 +8,6 @@ import 'package:openapi/api.dart';
 ## Properties
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
-**className** | **String** |  | 
-**color** | **String** |  | [optional] [default to 'red']
 **declawed** | **bool** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/ChildWithNullable.md b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/ChildWithNullable.md
index 770494fcf4cc..c0cb6b933d9f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/ChildWithNullable.md
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/ChildWithNullable.md
@@ -8,8 +8,6 @@ import 'package:openapi/api.dart';
 ## Properties
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
-**type** | **String** |  | [optional] 
-**nullableProperty** | **String** |  | [optional] 
 **otherProperty** | **String** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Dog.md b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Dog.md
index d36439b767bb..ef7ff6e8ac12 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Dog.md
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/doc/Dog.md
@@ -8,8 +8,6 @@ import 'package:openapi/api.dart';
 ## Properties
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
-**className** | **String** |  | 
-**color** | **String** |  | [optional] [default to 'red']
 **breed** | **String** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/additional_properties_class.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/additional_properties_class.dart
index cfbc5ef08f77..dd2b471c22af 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/additional_properties_class.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/additional_properties_class.dart
@@ -17,13 +17,10 @@ part 'additional_properties_class.g.dart';
   explicitToJson: true,
 )
 class AdditionalPropertiesClass {
-  /// Returns a new [AdditionalPropertiesClass] instance.
+/// Returns a new [AdditionalPropertiesClass] instance.
   AdditionalPropertiesClass({
-
      this.mapProperty,
-
      this.mapOfMapProperty,
-
      this.mapOfArrayInteger,
   });
 
@@ -67,6 +64,7 @@ class AdditionalPropertiesClass {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is AdditionalPropertiesClass &&
+    runtimeType == other.runtimeType &&
       other.mapProperty == mapProperty &&
       other.mapOfMapProperty == mapOfMapProperty &&
       other.mapOfArrayInteger == mapOfArrayInteger;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/all_of_with_single_ref.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/all_of_with_single_ref.dart
index 775b58a1fca6..9859a417c7a2 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/all_of_with_single_ref.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/all_of_with_single_ref.dart
@@ -18,11 +18,9 @@ part 'all_of_with_single_ref.g.dart';
   explicitToJson: true,
 )
 class AllOfWithSingleRef {
-  /// Returns a new [AllOfWithSingleRef] instance.
+/// Returns a new [AllOfWithSingleRef] instance.
   AllOfWithSingleRef({
-
      this.username,
-
      this.singleRefType,
   });
 
@@ -55,6 +53,7 @@ class AllOfWithSingleRef {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is AllOfWithSingleRef &&
+    runtimeType == other.runtimeType &&
       other.username == username &&
       other.singleRefType == singleRefType;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/animal.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/animal.dart
index c9abb12b9308..ce9c03aa0681 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/animal.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/animal.dart
@@ -17,11 +17,9 @@ part 'animal.g.dart';
   explicitToJson: true,
 )
 class Animal {
-  /// Returns a new [Animal] instance.
+/// Returns a new [Animal] instance.
   Animal({
-
     required  this.className,
-
      this.color = 'red',
   });
 
@@ -53,6 +51,7 @@ class Animal {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Animal &&
+    runtimeType == other.runtimeType &&
       other.className == className &&
       other.color == color;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/api_response.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/api_response.dart
index d1b0fa6294ee..c11b92f2ea1a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/api_response.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/api_response.dart
@@ -17,13 +17,10 @@ part 'api_response.g.dart';
   explicitToJson: true,
 )
 class ApiResponse {
-  /// Returns a new [ApiResponse] instance.
+/// Returns a new [ApiResponse] instance.
   ApiResponse({
-
      this.code,
-
      this.type,
-
      this.message,
   });
 
@@ -67,6 +64,7 @@ class ApiResponse {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ApiResponse &&
+    runtimeType == other.runtimeType &&
       other.code == code &&
       other.type == type &&
       other.message == message;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_array_of_number_only.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_array_of_number_only.dart
index e0e2d78b95b7..36679c9121f6 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_array_of_number_only.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_array_of_number_only.dart
@@ -17,9 +17,8 @@ part 'array_of_array_of_number_only.g.dart';
   explicitToJson: true,
 )
 class ArrayOfArrayOfNumberOnly {
-  /// Returns a new [ArrayOfArrayOfNumberOnly] instance.
+/// Returns a new [ArrayOfArrayOfNumberOnly] instance.
   ArrayOfArrayOfNumberOnly({
-
      this.arrayArrayNumber,
   });
 
@@ -39,6 +38,7 @@ class ArrayOfArrayOfNumberOnly {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ArrayOfArrayOfNumberOnly &&
+    runtimeType == other.runtimeType &&
       other.arrayArrayNumber == arrayArrayNumber;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_number_only.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_number_only.dart
index 9d9e0a197a2f..814123300094 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_number_only.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_of_number_only.dart
@@ -17,9 +17,8 @@ part 'array_of_number_only.g.dart';
   explicitToJson: true,
 )
 class ArrayOfNumberOnly {
-  /// Returns a new [ArrayOfNumberOnly] instance.
+/// Returns a new [ArrayOfNumberOnly] instance.
   ArrayOfNumberOnly({
-
      this.arrayNumber,
   });
 
@@ -39,6 +38,7 @@ class ArrayOfNumberOnly {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ArrayOfNumberOnly &&
+    runtimeType == other.runtimeType &&
       other.arrayNumber == arrayNumber;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_test.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_test.dart
index 30fdd53ab675..f88af5406a76 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_test.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/array_test.dart
@@ -18,13 +18,10 @@ part 'array_test.g.dart';
   explicitToJson: true,
 )
 class ArrayTest {
-  /// Returns a new [ArrayTest] instance.
+/// Returns a new [ArrayTest] instance.
   ArrayTest({
-
      this.arrayOfString,
-
      this.arrayArrayOfInteger,
-
      this.arrayArrayOfModel,
   });
 
@@ -68,6 +65,7 @@ class ArrayTest {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ArrayTest &&
+    runtimeType == other.runtimeType &&
       other.arrayOfString == arrayOfString &&
       other.arrayArrayOfInteger == arrayArrayOfInteger &&
       other.arrayArrayOfModel == arrayArrayOfModel;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/capitalization.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/capitalization.dart
index c2327b44f125..036ea3a52bfd 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/capitalization.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/capitalization.dart
@@ -17,19 +17,13 @@ part 'capitalization.g.dart';
   explicitToJson: true,
 )
 class Capitalization {
-  /// Returns a new [Capitalization] instance.
+/// Returns a new [Capitalization] instance.
   Capitalization({
-
      this.smallCamel,
-
      this.capitalCamel,
-
      this.smallSnake,
-
      this.capitalSnake,
-
      this.sCAETHFlowPoints,
-
      this.ATT_NAME,
   });
 
@@ -110,6 +104,7 @@ class Capitalization {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Capitalization &&
+    runtimeType == other.runtimeType &&
       other.smallCamel == smallCamel &&
       other.capitalCamel == capitalCamel &&
       other.smallSnake == smallSnake &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/cat.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/cat.dart
index 05eebe01a67e..bc3567ca61a2 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/cat.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/cat.dart
@@ -19,41 +19,14 @@ part 'cat.g.dart';
   disallowUnrecognizedKeys: false,
   explicitToJson: true,
 )
-class Cat {
-  /// Returns a new [Cat] instance.
+class Cat extends Animal {
+/// Returns a new [Cat] instance.
   Cat({
-
-    required  this.className,
-
-     this.color = 'red',
-
      this.declawed,
+    required  super.className,
+     super.color = 'red',
   });
 
-  @JsonKey(
-    
-    name: r'className',
-    required: true,
-    includeIfNull: false,
-  )
-
-
-  final String className;
-
-
-
-  @JsonKey(
-    defaultValue: 'red',
-    name: r'color',
-    required: false,
-    includeIfNull: false,
-  )
-
-
-  final String? color;
-
-
-
   @JsonKey(
     
     name: r'declawed',
@@ -70,6 +43,7 @@ class Cat {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Cat &&
+    runtimeType == other.runtimeType &&
       other.className == className &&
       other.color == color &&
       other.declawed == declawed;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/category.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/category.dart
index 35718dc06d5b..ec54786b2b6f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/category.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/category.dart
@@ -17,11 +17,9 @@ part 'category.g.dart';
   explicitToJson: true,
 )
 class Category {
-  /// Returns a new [Category] instance.
+/// Returns a new [Category] instance.
   Category({
-
      this.id,
-
      this.name = 'default-name',
   });
 
@@ -53,6 +51,7 @@ class Category {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Category &&
+    runtimeType == other.runtimeType &&
       other.id == id &&
       other.name == name;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/child_with_nullable.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/child_with_nullable.dart
index f0e430001673..aa0dcae122fa 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/child_with_nullable.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/child_with_nullable.dart
@@ -19,41 +19,14 @@ part 'child_with_nullable.g.dart';
   disallowUnrecognizedKeys: false,
   explicitToJson: true,
 )
-class ChildWithNullable {
-  /// Returns a new [ChildWithNullable] instance.
+class ChildWithNullable extends ParentWithNullable {
+/// Returns a new [ChildWithNullable] instance.
   ChildWithNullable({
-
-     this.type,
-
-     this.nullableProperty,
-
      this.otherProperty,
+     super.type,
+     super.nullableProperty,
   });
 
-  @JsonKey(
-    
-    name: r'type',
-    required: false,
-    includeIfNull: false,
-  )
-
-
-  final String? type;
-
-
-
-  @JsonKey(
-    
-    name: r'nullableProperty',
-    required: false,
-    includeIfNull: false,
-  )
-
-
-  final String? nullableProperty;
-
-
-
   @JsonKey(
     
     name: r'otherProperty',
@@ -70,6 +43,7 @@ class ChildWithNullable {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ChildWithNullable &&
+    runtimeType == other.runtimeType &&
       other.type == type &&
       other.nullableProperty == nullableProperty &&
       other.otherProperty == otherProperty;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/class_model.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/class_model.dart
index 8802de37921e..ae809ca4f9a2 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/class_model.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/class_model.dart
@@ -17,9 +17,8 @@ part 'class_model.g.dart';
   explicitToJson: true,
 )
 class ClassModel {
-  /// Returns a new [ClassModel] instance.
+/// Returns a new [ClassModel] instance.
   ClassModel({
-
      this.class_,
   });
 
@@ -39,6 +38,7 @@ class ClassModel {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ClassModel &&
+    runtimeType == other.runtimeType &&
       other.class_ == class_;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/deprecated_object.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/deprecated_object.dart
index 844cda541b83..8d086e58169f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/deprecated_object.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/deprecated_object.dart
@@ -18,9 +18,8 @@ part 'deprecated_object.g.dart';
   explicitToJson: true,
 )
 class DeprecatedObject {
-  /// Returns a new [DeprecatedObject] instance.
+/// Returns a new [DeprecatedObject] instance.
   DeprecatedObject({
-
      this.name,
   });
 
@@ -40,6 +39,7 @@ class DeprecatedObject {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is DeprecatedObject &&
+    runtimeType == other.runtimeType &&
       other.name == name;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/dog.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/dog.dart
index 9dd6a37ffcee..4ca9a80b2a8f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/dog.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/dog.dart
@@ -19,41 +19,14 @@ part 'dog.g.dart';
   disallowUnrecognizedKeys: false,
   explicitToJson: true,
 )
-class Dog {
-  /// Returns a new [Dog] instance.
+class Dog extends Animal {
+/// Returns a new [Dog] instance.
   Dog({
-
-    required  this.className,
-
-     this.color = 'red',
-
      this.breed,
+    required  super.className,
+     super.color = 'red',
   });
 
-  @JsonKey(
-    
-    name: r'className',
-    required: true,
-    includeIfNull: false,
-  )
-
-
-  final String className;
-
-
-
-  @JsonKey(
-    defaultValue: 'red',
-    name: r'color',
-    required: false,
-    includeIfNull: false,
-  )
-
-
-  final String? color;
-
-
-
   @JsonKey(
     
     name: r'breed',
@@ -70,6 +43,7 @@ class Dog {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Dog &&
+    runtimeType == other.runtimeType &&
       other.className == className &&
       other.color == color &&
       other.breed == breed;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_arrays.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_arrays.dart
index b1d9f2942b1d..5049e81370a1 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_arrays.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_arrays.dart
@@ -17,11 +17,9 @@ part 'enum_arrays.g.dart';
   explicitToJson: true,
 )
 class EnumArrays {
-  /// Returns a new [EnumArrays] instance.
+/// Returns a new [EnumArrays] instance.
   EnumArrays({
-
      this.justSymbol,
-
      this.arrayEnum,
   });
 
@@ -55,6 +53,7 @@ class EnumArrays {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is EnumArrays &&
+    runtimeType == other.runtimeType &&
       other.justSymbol == justSymbol &&
       other.arrayEnum == arrayEnum;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_test.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_test.dart
index 1563c30bece7..5633122d7196 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_test.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/enum_test.dart
@@ -21,23 +21,15 @@ part 'enum_test.g.dart';
   explicitToJson: true,
 )
 class EnumTest {
-  /// Returns a new [EnumTest] instance.
+/// Returns a new [EnumTest] instance.
   EnumTest({
-
      this.enumString,
-
     required  this.enumStringRequired,
-
      this.enumInteger,
-
      this.enumNumber,
-
      this.outerEnum,
-
      this.outerEnumInteger,
-
      this.outerEnumDefaultValue,
-
      this.outerEnumIntegerDefaultValue,
   });
 
@@ -149,6 +141,7 @@ class EnumTest {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is EnumTest &&
+    runtimeType == other.runtimeType &&
       other.enumString == enumString &&
       other.enumStringRequired == enumStringRequired &&
       other.enumInteger == enumInteger &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/fake_big_decimal_map200_response.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/fake_big_decimal_map200_response.dart
index e15b863e9218..1964074ebfbc 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/fake_big_decimal_map200_response.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/fake_big_decimal_map200_response.dart
@@ -17,11 +17,9 @@ part 'fake_big_decimal_map200_response.g.dart';
   explicitToJson: true,
 )
 class FakeBigDecimalMap200Response {
-  /// Returns a new [FakeBigDecimalMap200Response] instance.
+/// Returns a new [FakeBigDecimalMap200Response] instance.
   FakeBigDecimalMap200Response({
-
      this.someId,
-
      this.someMap,
   });
 
@@ -53,6 +51,7 @@ class FakeBigDecimalMap200Response {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is FakeBigDecimalMap200Response &&
+    runtimeType == other.runtimeType &&
       other.someId == someId &&
       other.someMap == someMap;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/file_schema_test_class.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/file_schema_test_class.dart
index 43307b721b15..b701d3d4418b 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/file_schema_test_class.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/file_schema_test_class.dart
@@ -18,11 +18,9 @@ part 'file_schema_test_class.g.dart';
   explicitToJson: true,
 )
 class FileSchemaTestClass {
-  /// Returns a new [FileSchemaTestClass] instance.
+/// Returns a new [FileSchemaTestClass] instance.
   FileSchemaTestClass({
-
      this.file,
-
      this.files,
   });
 
@@ -54,6 +52,7 @@ class FileSchemaTestClass {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is FileSchemaTestClass &&
+    runtimeType == other.runtimeType &&
       other.file == file &&
       other.files == files;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo.dart
index 0f214c4e6ff8..1948a67c078d 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo.dart
@@ -17,9 +17,8 @@ part 'foo.g.dart';
   explicitToJson: true,
 )
 class Foo {
-  /// Returns a new [Foo] instance.
+/// Returns a new [Foo] instance.
   Foo({
-
      this.bar = 'bar',
   });
 
@@ -39,6 +38,7 @@ class Foo {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Foo &&
+    runtimeType == other.runtimeType &&
       other.bar == bar;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo_get_default_response.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo_get_default_response.dart
index 6a072cd6634b..7c30090dd707 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo_get_default_response.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/foo_get_default_response.dart
@@ -18,9 +18,8 @@ part 'foo_get_default_response.g.dart';
   explicitToJson: true,
 )
 class FooGetDefaultResponse {
-  /// Returns a new [FooGetDefaultResponse] instance.
+/// Returns a new [FooGetDefaultResponse] instance.
   FooGetDefaultResponse({
-
      this.string,
   });
 
@@ -40,6 +39,7 @@ class FooGetDefaultResponse {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is FooGetDefaultResponse &&
+    runtimeType == other.runtimeType &&
       other.string == string;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/format_test.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/format_test.dart
index 1f8c47a279f7..605e6963f41d 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/format_test.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/format_test.dart
@@ -18,39 +18,23 @@ part 'format_test.g.dart';
   explicitToJson: true,
 )
 class FormatTest {
-  /// Returns a new [FormatTest] instance.
+/// Returns a new [FormatTest] instance.
   FormatTest({
-
      this.integer,
-
      this.int32,
-
      this.int64,
-
     required  this.number,
-
      this.float,
-
      this.double_,
-
      this.decimal,
-
      this.string,
-
     required  this.byte,
-
      this.binary,
-
     required  this.date,
-
      this.dateTime,
-
      this.uuid,
-
     required  this.password,
-
      this.patternWithDigits,
-
      this.patternWithDigitsAndDelimiter,
   });
 
@@ -257,6 +241,7 @@ class FormatTest {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is FormatTest &&
+    runtimeType == other.runtimeType &&
       other.integer == integer &&
       other.int32 == int32 &&
       other.int64 == int64 &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/has_only_read_only.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/has_only_read_only.dart
index d224cbcf15dd..dc319df07740 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/has_only_read_only.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/has_only_read_only.dart
@@ -17,11 +17,9 @@ part 'has_only_read_only.g.dart';
   explicitToJson: true,
 )
 class HasOnlyReadOnly {
-  /// Returns a new [HasOnlyReadOnly] instance.
+/// Returns a new [HasOnlyReadOnly] instance.
   HasOnlyReadOnly({
-
      this.bar,
-
      this.foo,
   });
 
@@ -53,6 +51,7 @@ class HasOnlyReadOnly {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is HasOnlyReadOnly &&
+    runtimeType == other.runtimeType &&
       other.bar == bar &&
       other.foo == foo;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/health_check_result.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/health_check_result.dart
index 38dcfcacddca..7f5230aaa6d9 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/health_check_result.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/health_check_result.dart
@@ -17,9 +17,8 @@ part 'health_check_result.g.dart';
   explicitToJson: true,
 )
 class HealthCheckResult {
-  /// Returns a new [HealthCheckResult] instance.
+/// Returns a new [HealthCheckResult] instance.
   HealthCheckResult({
-
      this.nullableMessage,
   });
 
@@ -39,6 +38,7 @@ class HealthCheckResult {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is HealthCheckResult &&
+    runtimeType == other.runtimeType &&
       other.nullableMessage == nullableMessage;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/map_test.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/map_test.dart
index 4a84fa85524f..1d8e8767f227 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/map_test.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/map_test.dart
@@ -17,15 +17,11 @@ part 'map_test.g.dart';
   explicitToJson: true,
 )
 class MapTest {
-  /// Returns a new [MapTest] instance.
+/// Returns a new [MapTest] instance.
   MapTest({
-
      this.mapMapOfString,
-
      this.mapOfEnumString,
-
      this.directMap,
-
      this.indirectMap,
   });
 
@@ -82,6 +78,7 @@ class MapTest {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is MapTest &&
+    runtimeType == other.runtimeType &&
       other.mapMapOfString == mapMapOfString &&
       other.mapOfEnumString == mapOfEnumString &&
       other.directMap == directMap &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/mixed_properties_and_additional_properties_class.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/mixed_properties_and_additional_properties_class.dart
index 63bc9d15ceda..40bb81c2167b 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/mixed_properties_and_additional_properties_class.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/mixed_properties_and_additional_properties_class.dart
@@ -18,13 +18,10 @@ part 'mixed_properties_and_additional_properties_class.g.dart';
   explicitToJson: true,
 )
 class MixedPropertiesAndAdditionalPropertiesClass {
-  /// Returns a new [MixedPropertiesAndAdditionalPropertiesClass] instance.
+/// Returns a new [MixedPropertiesAndAdditionalPropertiesClass] instance.
   MixedPropertiesAndAdditionalPropertiesClass({
-
      this.uuid,
-
      this.dateTime,
-
      this.map,
   });
 
@@ -68,6 +65,7 @@ class MixedPropertiesAndAdditionalPropertiesClass {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is MixedPropertiesAndAdditionalPropertiesClass &&
+    runtimeType == other.runtimeType &&
       other.uuid == uuid &&
       other.dateTime == dateTime &&
       other.map == map;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model200_response.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model200_response.dart
index bee419bd3ee9..fb665d7c1b8a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model200_response.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model200_response.dart
@@ -17,11 +17,9 @@ part 'model200_response.g.dart';
   explicitToJson: true,
 )
 class Model200Response {
-  /// Returns a new [Model200Response] instance.
+/// Returns a new [Model200Response] instance.
   Model200Response({
-
      this.name,
-
      this.class_,
   });
 
@@ -53,6 +51,7 @@ class Model200Response {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Model200Response &&
+    runtimeType == other.runtimeType &&
       other.name == name &&
       other.class_ == class_;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_client.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_client.dart
index d6fef8505390..9c27e1a82d76 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_client.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_client.dart
@@ -17,9 +17,8 @@ part 'model_client.g.dart';
   explicitToJson: true,
 )
 class ModelClient {
-  /// Returns a new [ModelClient] instance.
+/// Returns a new [ModelClient] instance.
   ModelClient({
-
      this.client,
   });
 
@@ -39,6 +38,7 @@ class ModelClient {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ModelClient &&
+    runtimeType == other.runtimeType &&
       other.client == client;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_file.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_file.dart
index c34131e2940f..14ddd1ecd46f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_file.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_file.dart
@@ -17,9 +17,8 @@ part 'model_file.g.dart';
   explicitToJson: true,
 )
 class ModelFile {
-  /// Returns a new [ModelFile] instance.
+/// Returns a new [ModelFile] instance.
   ModelFile({
-
      this.sourceURI,
   });
 
@@ -40,6 +39,7 @@ class ModelFile {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ModelFile &&
+    runtimeType == other.runtimeType &&
       other.sourceURI == sourceURI;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_list.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_list.dart
index c99439660de6..5ed275184b68 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_list.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_list.dart
@@ -17,9 +17,8 @@ part 'model_list.g.dart';
   explicitToJson: true,
 )
 class ModelList {
-  /// Returns a new [ModelList] instance.
+/// Returns a new [ModelList] instance.
   ModelList({
-
      this.n123list,
   });
 
@@ -39,6 +38,7 @@ class ModelList {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ModelList &&
+    runtimeType == other.runtimeType &&
       other.n123list == n123list;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_return.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_return.dart
index c29886c95b7e..4b2e9407cdf6 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_return.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/model_return.dart
@@ -17,9 +17,8 @@ part 'model_return.g.dart';
   explicitToJson: true,
 )
 class ModelReturn {
-  /// Returns a new [ModelReturn] instance.
+/// Returns a new [ModelReturn] instance.
   ModelReturn({
-
      this.return_,
   });
 
@@ -39,6 +38,7 @@ class ModelReturn {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ModelReturn &&
+    runtimeType == other.runtimeType &&
       other.return_ == return_;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/name.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/name.dart
index 787a603a97fe..180f61890a4b 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/name.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/name.dart
@@ -17,15 +17,11 @@ part 'name.g.dart';
   explicitToJson: true,
 )
 class Name {
-  /// Returns a new [Name] instance.
+/// Returns a new [Name] instance.
   Name({
-
     required  this.name,
-
      this.snakeCase,
-
      this.property,
-
      this.n123number,
   });
 
@@ -81,6 +77,7 @@ class Name {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Name &&
+    runtimeType == other.runtimeType &&
       other.name == name &&
       other.snakeCase == snakeCase &&
       other.property == property &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/nullable_class.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/nullable_class.dart
index 0ffb6db0f33f..871c69cff78e 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/nullable_class.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/nullable_class.dart
@@ -16,32 +16,20 @@ part 'nullable_class.g.dart';
   disallowUnrecognizedKeys: false,
   explicitToJson: true,
 )
-class NullableClass {
-  /// Returns a new [NullableClass] instance.
+class NullableClass extends Object {
+/// Returns a new [NullableClass] instance.
   NullableClass({
-
      this.integerProp,
-
      this.numberProp,
-
      this.booleanProp,
-
      this.stringProp,
-
      this.dateProp,
-
      this.datetimeProp,
-
      this.arrayNullableProp,
-
      this.arrayAndItemsNullableProp,
-
      this.arrayItemsNullable,
-
      this.objectNullableProp,
-
      this.objectAndItemsNullableProp,
-
      this.objectItemsNullable,
   });
 
@@ -193,6 +181,7 @@ class NullableClass {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is NullableClass &&
+    runtimeType == other.runtimeType &&
       other.integerProp == integerProp &&
       other.numberProp == numberProp &&
       other.booleanProp == booleanProp &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/number_only.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/number_only.dart
index 2e8ff4201b8a..4bc7e04ea9f8 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/number_only.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/number_only.dart
@@ -17,9 +17,8 @@ part 'number_only.g.dart';
   explicitToJson: true,
 )
 class NumberOnly {
-  /// Returns a new [NumberOnly] instance.
+/// Returns a new [NumberOnly] instance.
   NumberOnly({
-
      this.justNumber,
   });
 
@@ -39,6 +38,7 @@ class NumberOnly {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is NumberOnly &&
+    runtimeType == other.runtimeType &&
       other.justNumber == justNumber;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_that_references_objects_with_duplicate_inline_enums.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_that_references_objects_with_duplicate_inline_enums.dart
index f75412a52d6c..411d91cb3a4a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_that_references_objects_with_duplicate_inline_enums.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_that_references_objects_with_duplicate_inline_enums.dart
@@ -19,11 +19,9 @@ part 'object_that_references_objects_with_duplicate_inline_enums.g.dart';
   explicitToJson: true,
 )
 class ObjectThatReferencesObjectsWithDuplicateInlineEnums {
-  /// Returns a new [ObjectThatReferencesObjectsWithDuplicateInlineEnums] instance.
+/// Returns a new [ObjectThatReferencesObjectsWithDuplicateInlineEnums] instance.
   ObjectThatReferencesObjectsWithDuplicateInlineEnums({
-
      this.objectOne,
-
      this.objectTwo,
   });
 
@@ -55,6 +53,7 @@ class ObjectThatReferencesObjectsWithDuplicateInlineEnums {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ObjectThatReferencesObjectsWithDuplicateInlineEnums &&
+    runtimeType == other.runtimeType &&
       other.objectOne == objectOne &&
       other.objectTwo == objectTwo;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_deprecated_fields.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_deprecated_fields.dart
index e2a95d308514..1ea6d30e1929 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_deprecated_fields.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_deprecated_fields.dart
@@ -18,15 +18,11 @@ part 'object_with_deprecated_fields.g.dart';
   explicitToJson: true,
 )
 class ObjectWithDeprecatedFields {
-  /// Returns a new [ObjectWithDeprecatedFields] instance.
+/// Returns a new [ObjectWithDeprecatedFields] instance.
   ObjectWithDeprecatedFields({
-
      this.uuid,
-
      this.id,
-
      this.deprecatedRef,
-
      this.bars,
   });
 
@@ -85,6 +81,7 @@ class ObjectWithDeprecatedFields {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ObjectWithDeprecatedFields &&
+    runtimeType == other.runtimeType &&
       other.uuid == uuid &&
       other.id == id &&
       other.deprecatedRef == deprecatedRef &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_duplicate_inline_enum.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_duplicate_inline_enum.dart
index 4734312e79e2..a8d05af84fbe 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_duplicate_inline_enum.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_duplicate_inline_enum.dart
@@ -17,9 +17,8 @@ part 'object_with_duplicate_inline_enum.g.dart';
   explicitToJson: true,
 )
 class ObjectWithDuplicateInlineEnum {
-  /// Returns a new [ObjectWithDuplicateInlineEnum] instance.
+/// Returns a new [ObjectWithDuplicateInlineEnum] instance.
   ObjectWithDuplicateInlineEnum({
-
      this.attribute,
   });
 
@@ -41,6 +40,7 @@ class ObjectWithDuplicateInlineEnum {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ObjectWithDuplicateInlineEnum &&
+    runtimeType == other.runtimeType &&
       other.attribute == attribute;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_enum.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_enum.dart
index 7cbf5091e596..87b71c80dad4 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_enum.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_enum.dart
@@ -18,9 +18,8 @@ part 'object_with_enum.g.dart';
   explicitToJson: true,
 )
 class ObjectWithEnum {
-  /// Returns a new [ObjectWithEnum] instance.
+/// Returns a new [ObjectWithEnum] instance.
   ObjectWithEnum({
-
      this.attribute = TestEnum.empty,
   });
 
@@ -41,6 +40,7 @@ class ObjectWithEnum {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ObjectWithEnum &&
+    runtimeType == other.runtimeType &&
       other.attribute == attribute;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum.dart
index 48e01ea5d998..34810583dd69 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum.dart
@@ -17,9 +17,8 @@ part 'object_with_inline_enum.g.dart';
   explicitToJson: true,
 )
 class ObjectWithInlineEnum {
-  /// Returns a new [ObjectWithInlineEnum] instance.
+/// Returns a new [ObjectWithInlineEnum] instance.
   ObjectWithInlineEnum({
-
      this.attribute,
   });
 
@@ -41,6 +40,7 @@ class ObjectWithInlineEnum {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ObjectWithInlineEnum &&
+    runtimeType == other.runtimeType &&
       other.attribute == attribute;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum_default_value.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum_default_value.dart
index 289025e07a44..d8bc76671fad 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum_default_value.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/object_with_inline_enum_default_value.dart
@@ -17,9 +17,8 @@ part 'object_with_inline_enum_default_value.g.dart';
   explicitToJson: true,
 )
 class ObjectWithInlineEnumDefaultValue {
-  /// Returns a new [ObjectWithInlineEnumDefaultValue] instance.
+/// Returns a new [ObjectWithInlineEnumDefaultValue] instance.
   ObjectWithInlineEnumDefaultValue({
-
      this.attribute = const ObjectWithInlineEnumDefaultValueAttributeEnum._('value_one'),
   });
 
@@ -41,6 +40,7 @@ class ObjectWithInlineEnumDefaultValue {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ObjectWithInlineEnumDefaultValue &&
+    runtimeType == other.runtimeType &&
       other.attribute == attribute;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/order.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/order.dart
index e50a3e70e819..0b6f6b0db3de 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/order.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/order.dart
@@ -17,19 +17,13 @@ part 'order.g.dart';
   explicitToJson: true,
 )
 class Order {
-  /// Returns a new [Order] instance.
+/// Returns a new [Order] instance.
   Order({
-
      this.id,
-
      this.petId,
-
      this.quantity,
-
      this.shipDate,
-
      this.status,
-
      this.complete = false,
   });
 
@@ -111,6 +105,7 @@ class Order {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Order &&
+    runtimeType == other.runtimeType &&
       other.id == id &&
       other.petId == petId &&
       other.quantity == quantity &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_composite.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_composite.dart
index 66a78af39ebc..2c597e8d448a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_composite.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_composite.dart
@@ -17,13 +17,10 @@ part 'outer_composite.g.dart';
   explicitToJson: true,
 )
 class OuterComposite {
-  /// Returns a new [OuterComposite] instance.
+/// Returns a new [OuterComposite] instance.
   OuterComposite({
-
      this.myNumber,
-
      this.myString,
-
      this.myBoolean,
   });
 
@@ -67,6 +64,7 @@ class OuterComposite {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is OuterComposite &&
+    runtimeType == other.runtimeType &&
       other.myNumber == myNumber &&
       other.myString == myString &&
       other.myBoolean == myBoolean;
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_object_with_enum_property.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_object_with_enum_property.dart
index 2708a3d953fd..f7b1ce7279c7 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_object_with_enum_property.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/outer_object_with_enum_property.dart
@@ -18,9 +18,8 @@ part 'outer_object_with_enum_property.g.dart';
   explicitToJson: true,
 )
 class OuterObjectWithEnumProperty {
-  /// Returns a new [OuterObjectWithEnumProperty] instance.
+/// Returns a new [OuterObjectWithEnumProperty] instance.
   OuterObjectWithEnumProperty({
-
     required  this.value,
   });
 
@@ -41,6 +40,7 @@ class OuterObjectWithEnumProperty {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is OuterObjectWithEnumProperty &&
+    runtimeType == other.runtimeType &&
       other.value == value;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/parent_with_nullable.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/parent_with_nullable.dart
index 121cf835d54d..8a9ebf3925ee 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/parent_with_nullable.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/parent_with_nullable.dart
@@ -17,11 +17,9 @@ part 'parent_with_nullable.g.dart';
   explicitToJson: true,
 )
 class ParentWithNullable {
-  /// Returns a new [ParentWithNullable] instance.
+/// Returns a new [ParentWithNullable] instance.
   ParentWithNullable({
-
      this.type,
-
      this.nullableProperty,
   });
 
@@ -53,6 +51,7 @@ class ParentWithNullable {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ParentWithNullable &&
+    runtimeType == other.runtimeType &&
       other.type == type &&
       other.nullableProperty == nullableProperty;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/pet.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/pet.dart
index b2674ae99fc6..5d8e258f7f32 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/pet.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/pet.dart
@@ -19,19 +19,13 @@ part 'pet.g.dart';
   explicitToJson: true,
 )
 class Pet {
-  /// Returns a new [Pet] instance.
+/// Returns a new [Pet] instance.
   Pet({
-
      this.id,
-
      this.category,
-
     required  this.name,
-
     required  this.photoUrls,
-
      this.tags,
-
      this.status,
   });
 
@@ -113,6 +107,7 @@ class Pet {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Pet &&
+    runtimeType == other.runtimeType &&
       other.id == id &&
       other.category == category &&
       other.name == name &&
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/read_only_first.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/read_only_first.dart
index d276ea105f41..2e159fb0384c 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/read_only_first.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/read_only_first.dart
@@ -17,11 +17,9 @@ part 'read_only_first.g.dart';
   explicitToJson: true,
 )
 class ReadOnlyFirst {
-  /// Returns a new [ReadOnlyFirst] instance.
+/// Returns a new [ReadOnlyFirst] instance.
   ReadOnlyFirst({
-
      this.bar,
-
      this.baz,
   });
 
@@ -53,6 +51,7 @@ class ReadOnlyFirst {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is ReadOnlyFirst &&
+    runtimeType == other.runtimeType &&
       other.bar == bar &&
       other.baz == baz;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/special_model_name.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/special_model_name.dart
index 37053ba18f7e..52a1e6c2ab0b 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/special_model_name.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/special_model_name.dart
@@ -17,9 +17,8 @@ part 'special_model_name.g.dart';
   explicitToJson: true,
 )
 class SpecialModelName {
-  /// Returns a new [SpecialModelName] instance.
+/// Returns a new [SpecialModelName] instance.
   SpecialModelName({
-
      this.dollarSpecialLeftSquareBracketPropertyPeriodNameRightSquareBracket,
   });
 
@@ -39,6 +38,7 @@ class SpecialModelName {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is SpecialModelName &&
+    runtimeType == other.runtimeType &&
       other.dollarSpecialLeftSquareBracketPropertyPeriodNameRightSquareBracket == dollarSpecialLeftSquareBracketPropertyPeriodNameRightSquareBracket;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/tag.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/tag.dart
index ca1d4ed43ebc..ed588ecc4a0a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/tag.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/tag.dart
@@ -17,11 +17,9 @@ part 'tag.g.dart';
   explicitToJson: true,
 )
 class Tag {
-  /// Returns a new [Tag] instance.
+/// Returns a new [Tag] instance.
   Tag({
-
      this.id,
-
      this.name,
   });
 
@@ -53,6 +51,7 @@ class Tag {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is Tag &&
+    runtimeType == other.runtimeType &&
       other.id == id &&
       other.name == name;
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/test_inline_freeform_additional_properties_request.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/test_inline_freeform_additional_properties_request.dart
index 2eb68120e147..ffb85a706573 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/test_inline_freeform_additional_properties_request.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/test_inline_freeform_additional_properties_request.dart
@@ -16,10 +16,9 @@ part 'test_inline_freeform_additional_properties_request.g.dart';
   disallowUnrecognizedKeys: false,
   explicitToJson: true,
 )
-class TestInlineFreeformAdditionalPropertiesRequest {
-  /// Returns a new [TestInlineFreeformAdditionalPropertiesRequest] instance.
+class TestInlineFreeformAdditionalPropertiesRequest extends Object {
+/// Returns a new [TestInlineFreeformAdditionalPropertiesRequest] instance.
   TestInlineFreeformAdditionalPropertiesRequest({
-
      this.someProperty,
   });
 
@@ -39,6 +38,7 @@ class TestInlineFreeformAdditionalPropertiesRequest {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is TestInlineFreeformAdditionalPropertiesRequest &&
+    runtimeType == other.runtimeType &&
       other.someProperty == someProperty;
 
     @override
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/user.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/user.dart
index 15e9b2a2eb61..6f7263dad157 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/user.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/model/user.dart
@@ -17,23 +17,15 @@ part 'user.g.dart';
   explicitToJson: true,
 )
 class User {
-  /// Returns a new [User] instance.
+/// Returns a new [User] instance.
   User({
-
      this.id,
-
      this.username,
-
      this.firstName,
-
      this.lastName,
-
      this.email,
-
      this.password,
-
      this.phone,
-
      this.userStatus,
   });
 
@@ -138,6 +130,7 @@ class User {
 
     @override
     bool operator ==(Object other) => identical(this, other) || other is User &&
+    runtimeType == other.runtimeType &&
       other.id == id &&
       other.username == username &&
       other.firstName == firstName &&