              for base in bases if hasattr(base, '_declared_fields')
              for name, f in base._declared_fields.items() if name not in known
          ]
  
          return OrderedDict(base_fields + fields)
  
      def __new__(cls, name, bases, attrs):
          attrs['_declared_fields'] = cls._get_declared_fields(bases, attrs)
          return super().__new__(cls, name, bases, attrs)
  
 
</s> remove         by_name = OrderedDict((f.name, f) for f in fields)
 </s> add         by_name = {f.name: f for f in fields} </s> remove     fields = OrderedDict()
 </s> add     fields = {} </s> remove         defaults = OrderedDict()
 </s> add         defaults = {} </s> remove     ])
 </s> add     } </s> remove             ])
 </s> add             }
        return dict(base_fields + fields)
              for base in bases if hasattr(base, '_declared_fields')
              for name, f in base._declared_fields.items() if name not in known
          ]
  
        return dict(base_fields + fields)
  
      def __new__(cls, name, bases, attrs):
          attrs['_declared_fields'] = cls._get_declared_fields(bases, attrs)
          return super().__new__(cls, name, bases, attrs)
  
keep keep keep keep replace keep keep keep keep keep
 Replaced `OrderedDict` with `dict` (#8964) 
rest_framework/serializers.py