code: def _get_retry_delay(cause):
      
      metadata = dict(cause.trailing_metadata())
      retry_info_pb = metadata.get("google.rpc.retryinfo-bin")
      if retry_info_pb is not None:
          retry_info = RetryInfo()
          retry_info.ParseFromString(retry_info_pb)
          nanos = retry_info.retry_delay.nanos
          return retry_info.retry_delay.seconds + nanos / 1.0e9
docs: Helper for :func:`_delay_until_retry`.
  
      :type exc: :class:`grpc.Call`
      :param exc: exception for aborted transaction
  
      :rtype: float
      :returns: seconds to wait before retrying the transaction.