old_contents: 
  from marshmallow_jsonapi.fields import HyperlinkRelated
  from marshmallow_jsonapi.utils import get_value_or_raise
  
  
  class IncludingHyperlinkRelated(HyperlinkRelated):
  
      def __init__(self, nestedObj, *args,  **kwargs):
          if callable(nestedObj):
              nestedObj = nestedObj(many=False)
          self.nestedObj = nestedObj
          super(IncludingHyperlinkRelated, self).__init__(*args, **kwargs)
  
      def add_resource_linkage(self, value):
          def render(item):
              attributes = self._extract_attributes(item)
              type_ = attributes.pop('type', self.type_)
              return {'type': type_,
                      'id': get_value_or_raise(self.id_field, item),
                      'attributes': attributes}
          if self.many:
              included_data = [render(each) for each in value]
          else:
              included_data = render(value)
          return included_data
  
      def _extract_attributes(self, value):
          sub = self.nestedObj.dump(value).data
          try:
              return sub["data"]["attributes"]
          except (KeyError, TypeError):
              # we are a classic type
              pass
          return sub
  
new_contents: 
  from marshmallow_jsonapi.fields import HyperlinkRelated
  from marshmallow_jsonapi.utils import get_value_or_raise
  
  
  class IncludingHyperlinkRelated(HyperlinkRelated):
  
      def __init__(self, nestedObj, *args,  **kwargs):
          if callable(nestedObj):
              nestedObj = nestedObj(many=False)
          self.nestedObj = nestedObj
          kwargs['type_'] = " "
          kwargs['include_data'] = True
          super(IncludingHyperlinkRelated, self).__init__(*args, **kwargs)
  
      def add_resource_linkage(self, value):
          def render(item):
              attributes = self._extract_attributes(item)
              type_ = attributes.pop('type', self.type_)
              return {'type': type_,
                      'id': get_value_or_raise(self.id_field, item),
                      'attributes': attributes}
          if self.many:
              included_data = [render(each) for each in value]
          else:
              included_data = render(value)
          return included_data
  
      def _extract_attributes(self, value):
          sub = self.nestedObj.dump(value).data
          try:
              return sub["data"]["attributes"]
          except (KeyError, TypeError):
              # we are a classic type
              pass
          return sub
  
subject: Enforce that our Including Hyperlink includes