code: def create_attachment(self, upload_stream, project=None, file_name=None, upload_type=None, area_path=None, **kwargs):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          query_parameters = {}
          if file_name is not None:
              query_parameters['fileName'] = self._serialize.query('file_name', file_name, 'str')
          if upload_type is not None:
              query_parameters['uploadType'] = self._serialize.query('upload_type', upload_type, 'str')
          if area_path is not None:
              query_parameters['areaPath'] = self._serialize.query('area_path', area_path, 'str')
          if "callback" in kwargs:
              callback = kwargs["callback"]
          else:
              callback = None
          content = self._client.stream_upload(upload_stream, callback=callback)
          response = self._send(http_method='POST',
                                location_id='e07b5fa4-1499-494d-a496-64b860fd64ff',
                                version='5.0',
                                route_values=route_values,
                                query_parameters=query_parameters,
                                content=content,
                                media_type='application/octet-stream')
          return self._deserialize('AttachmentReference', response)
docs: CreateAttachment.
          Uploads an attachment.
          :param object upload_stream: Stream to upload
          :param str project: Project ID or project name
          :param str file_name: The name of the file
          :param str upload_type: Attachment upload type: Simple or Chunked
          :param str area_path: Target project Area Path
          :rtype: :class:`<AttachmentReference> <azure.devops.v5_0.work_item_tracking.models.AttachmentReference>`