          Field.creation_counter += 1
  
          self.source = source
  
      def initialize(self, parent):
          """
          Called to set up a field prior to field_to_native or field_from_native.
  
          parent - The parent serializer.
          model_field - The model field this field corresponds to, if one exists.
 
</s> remove     def initialize(self, parent):
 </s> add     def initialize(self, parent, field_name): </s> remove             field.initialize(parent=self)
 </s> add             field.initialize(parent=self, field_name=key) </s> remove                 field.initialize(parent=self)
 </s> add                 field.initialize(parent=self, field_name=model_field.name) </s> remove         super(BaseSerializer, self).initialize(parent)
 </s> add         super(BaseSerializer, self).initialize(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)
    def initialize(self, parent, field_name):
          Field.creation_counter += 1
  
          self.source = source
  
    def initialize(self, parent, field_name):
          """
          Called to set up a field prior to field_to_native or field_from_native.
  
          parent - The parent serializer.
          model_field - The model field this field corresponds to, if one exists.
keep keep keep keep replace keep keep keep keep keep
 `queryset` argument is now optional on writable model fields. 
rest_framework/fields.py