          # Get the explicitly declared fields
          for key, field in self.fields.items():
              ret[key] = field
              # Set up the field
              field.initialize(parent=self)
  
          # Add in the default fields
          fields = self.default_fields(nested)
          for key, val in fields.items():
              if key not in ret:
 
</s> remove                 field.initialize(parent=self)
 </s> add                 field.initialize(parent=self, field_name=model_field.name) </s> remove     def initialize(self, parent):
 </s> add     def initialize(self, parent, field_name): </s> remove         self.fields = copy.deepcopy(self.base_fields)
 </s> add  </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     def restore_object(self, attrs, instance=None):
        return BlogPostComment(**attrs)
 </s> add     class Meta:
        model = BlogPostComment
        fields = ('text', 'blog_post_url')
            field.initialize(parent=self, field_name=key)
          # Get the explicitly declared fields
          for key, field in self.fields.items():
              ret[key] = field
              # Set up the field
            field.initialize(parent=self, field_name=key)
  
          # Add in the default fields
          fields = self.default_fields(nested)
          for key, val in fields.items():
              if key not in ret:
keep keep keep keep replace keep keep keep keep keep
 `queryset` argument is now optional on writable model fields. 
rest_framework/serializers.py