code: def validate_message(self, msg, *parameters):
          
          _, message_fields, header_fields = self._get_parameters_with_defaults(parameters)
          self._validate_message(msg, message_fields, header_fields)
docs: Validates given message using template defined with `New Message` and
          field values given as optional arguments.
  
          Examples:
          | Validate message | ${msg} |
          | Validate message | ${msg} | status:0 |