docs: def MultiSet(self,
                 subject,
                 values,
                 timestamp=None,
                 replace=True,
                 sync=True,
                 to_delete=None):
      """Set multiple attributes' values for this subject in one operation.
  
      Args:
        subject: The subject this applies to.
        values: A dict with keys containing attributes and values, serializations
          to be set. values can be a tuple of (value, timestamp). Value must be
          one of the supported types.
        timestamp: The timestamp for this entry in microseconds since the epoch.
          None means now.
        replace: Bool whether or not to overwrite current records.
        sync: If true we block until the operation completes.
        to_delete: An array of attributes to clear prior to setting.
      """