  
      #####
      # Field methods - used when the serializer class is itself used as a field.
  
      def initialize(self, parent):
          """
          Same behaviour as usual Field, except that we need to keep track
          of state so that we can deal with handling maximum depth.
          """
          super(BaseSerializer, self).initialize(parent)
 
</s> remove         super(BaseSerializer, self).initialize(parent)
 </s> add         super(BaseSerializer, self).initialize(parent, field_name) </s> remove     def initialize(self, parent):
 </s> add     def initialize(self, parent, field_name): </s> remove         self.read_only = self.default_read_only
 </s> add         self.read_only = kwargs.pop('read_only', self.default_read_only)

    def initialize(self, parent, field_name):
        super(RelatedField, self).initialize(parent, field_name)
        if self.queryset is None and not self.read_only:
            try:
                manager = getattr(self.parent.opts.model, self.source or field_name)
                if hasattr(manager, 'related'):  # Forward
                    self.queryset = manager.related.model._default_manager.all()
                else:  # Reverse
                    self.queryset = manager.field.rel.to._default_manager.all()
            except:
                raise
                msg = ('Serializer related fields must include a `queryset`' +
                       ' argument or set `read_only=True')
                raise Exception(msg) </s> remove             field.initialize(parent=self)
 </s> add             field.initialize(parent=self, field_name=key) </s> remove         self.fields = copy.deepcopy(self.base_fields)
 </s> add 
    def initialize(self, parent, field_name):
  
      #####
      # Field methods - used when the serializer class is itself used as a field.
  
    def initialize(self, parent, field_name):
          """
          Same behaviour as usual Field, except that we need to keep track
          of state so that we can deal with handling maximum depth.
          """
          super(BaseSerializer, self).initialize(parent)
keep keep keep keep replace keep keep keep keep keep
 `queryset` argument is now optional on writable model fields. 
rest_framework/serializers.py