      """
      _options_class = HyperlinkedModelSerializerOptions
      _default_view_name = '%(model_name)s-detail'
  
      url = HyperlinkedIdentityField()
  
      def __init__(self, *args, **kwargs):
          super(HyperlinkedModelSerializer, self).__init__(*args, **kwargs)
          if self.opts.view_name is None:
 
</s> remove         Get the name of a slug field to be used to look up by slug.
        """
        return self.slug_field

    def to_native(self, obj):
        view_name = self.view_name
        request = self.context.get('request', None)
        format = self.format or self.context.get('format', None)

        if request is None:
            warnings.warn("Using `HyperlinkedRelatedField` without including the "
                          "request in the serializer context is deprecated. "
                          "Add `context={'request': request}` when instantiating the serializer.",
                          DeprecationWarning, stacklevel=4)
 </s> add         Given an object, return the URL that hyperlinks to the object. </s> remove         self.format = kwargs.pop('format', None)
 </s> add  </s> remove         self.pk_url_kwarg = kwargs.pop('pk_url_kwarg', self.pk_url_kwarg)
 </s> add  </s> remove         return HyperlinkedRelatedField(**kwargs)
 </s> add         return self._hyperlink_field_class(**kwargs)
    _hyperlink_field_class = HyperlinkedRelatedField
      """
      _options_class = HyperlinkedModelSerializerOptions
      _default_view_name = '%(model_name)s-detail'
    _hyperlink_field_class = HyperlinkedRelatedField
  
      url = HyperlinkedIdentityField()
  
      def __init__(self, *args, **kwargs):
          super(HyperlinkedModelSerializer, self).__init__(*args, **kwargs)
          if self.opts.view_name is None:
keep keep add keep keep keep keep keep keep
 lookup_field on hyperlinked fields, and overriddable hyperlinked fields.  Closes #688 
rest_framework/serializers.py