code: def _GetMessage(self, event_object):
      
      # TODO: move this somewhere where the mediator can be instantiated once.
      formatter_mediator = formatters_mediator.FormatterMediator()
  
      result = ''
      try:
        result, _ = formatters_manager.FormattersManager.GetMessageStrings(
            formatter_mediator, event_object)
      except KeyError as exception:
        logging.warning(
            'Unable to correctly assemble event with error: {0!s}'.format(
                exception))
  
      return result
docs: Returns a properly formatted message string.
  
      Args:
        event_object: the event object (instance od EventObject).
  
      Returns:
        A formatted message string.