[BUG] [Dart] list comparison for and map comparison for ==

Description

For generated models, comparison of nested objects that are a list always return false due to the == comparison not working for list of objects in dart. Also for Maps of <type, Object> the same issue.

openapi-generator version

6.6.0

Suggest a fix

If using Flutter, when usually is the case, using listEquals(this.list, other.list) and mapEquals(this.map, other.map) works.
Just have to 'import 'package:flutter/foundation.dart'; into the api.dart file.

E.g.

  Obj({
    required this.id,
    this.data = const {},
    this.photos = const [],
  });
  
  String id,
  Map<String, Object> data;
  List<PhotoObject>?;
  
  @override
  bool operator ==(Object other)  => 
  identical(this, other) ||
            other is Obj  &&
            other.id == id &&
            other.data == data && 
            other.photos == photos
            
----- INTO ---------
  
  @override
  bool operator ==(Object other)  => 
  identical(this, other) ||
            other is Obj  &&
            other.id == id &&
            mapEquals(other.data, data) &&
            listEquals(other.photos, photos)

Start by locating the Dart generator code that produces the generated api.dart model equality methods, then inspect how nested List and Map fields are compared. Use the issue's Obj example as the expected behavior and verify that generated models compare these collections by contents rather than identity.