docs: def MultiDeleteAttributes(self,
                              subjects,
                              attributes,
                              start=None,
                              end=None,
                              sync=True):
      """Remove all specified attributes from a list of subjects.
  
      Args:
        subjects: The list of subjects that will have these attributes removed.
        attributes: A list of attributes.
        start: A timestamp, attributes older than start will not be deleted.
        end: A timestamp, attributes newer than end will not be deleted.
        sync: If true we block until the operation completes.
      """
      for subject in subjects:
        self.DeleteAttributes(
            subject, attributes, start=start, end=end, sync=sync)