          stream = self.stream
          media_type = self.content_type
  
          if stream is None or media_type is None:
              return (None, None)
  
          parser = self.negotiator.select_parser(self, self.parsers)
  
          if not parser:
              raise exceptions.UnsupportedMediaType(media_type)
 
</s> remove             return (parsed, None)
 </s> add             empty_files = MultiValueDict()
            return (parsed, empty_files) </s> remove         Ensure request.DATA returns None for HEAD request.
 </s> add         Ensure request.DATA returns empty QueryDict for HEAD request. </s> remove         self.assertEqual(request.DATA, None)
 </s> add         self.assertEqual(request.DATA, {}) </s> remove         self.assertEqual(request.DATA, None)
 </s> add         self.assertEqual(request.DATA, {}) </s> remove         Ensure request.DATA returns None for GET request with no content.
 </s> add         Ensure request.DATA returns empty QueryDict for GET request.
            empty_data = QueryDict('', self._request._encoding)
            empty_files = MultiValueDict()
            return (empty_data, empty_files)
          stream = self.stream
          media_type = self.content_type
  
          if stream is None or media_type is None:
            empty_data = QueryDict('', self._request._encoding)
            empty_files = MultiValueDict()
            return (empty_data, empty_files)
  
          parser = self.negotiator.select_parser(self, self.parsers)
  
          if not parser:
              raise exceptions.UnsupportedMediaType(media_type)
keep keep keep keep replace keep keep keep keep keep
 request.DATA should use empty QueryDict for no data, not None. 
rest_framework/request.py