          This hook is required for bulk update.
          We need to override the default, to use the url as the identity.
          """
          try:
              return data.get('url', None)
          except AttributeError:
              return None
  
      def _get_default_view_name(self, model):
          """
 
</s> remove             ret['url'] = url_field
 </s> add             ret[self.opts.url_field_name] = url_field </s> remove         if 'url' not in fields:
 </s> add         if self.opts.url_field_name not in fields:
            return data.get(self.opts.url_field_name, None)
          This hook is required for bulk update.
          We need to override the default, to use the url as the identity.
          """
          try:
            return data.get(self.opts.url_field_name, None)
          except AttributeError:
              return None
  
      def _get_default_view_name(self, model):
          """
keep keep keep keep replace keep keep keep keep keep
 Make HyperlinkedModelSerializer `url` field name customizable 
rest_framework/serializers.py