docs: def flushmany():
      """Send a potentially huge number of pending signals over the message bus.
  
      This command assumes that the number of pending signals might be
      huge, so that they might not fit into memory. However, it is not
      very smart in handling concurrent senders. It is mostly useful
      when recovering from long periods of disconnectedness from the
      message bus.
  
      """
  
      signalbus = current_app.extensions['signalbus']
      signal_count = signalbus.flushmany()
      logger = logging.getLogger(__name__)
      if signal_count == 1:
          logger.warning('%i signal has been successfully processed.', signal_count)
      elif signal_count > 1:
          logger.warning('%i signals have been successfully processed.', signal_count)