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.

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)