def METHOD_NAME(self, message: MessageDefinition) -> None:
    """Register a MessageDefinition with consistency in mind."""
    self.message_id_store.register_message_definition(
        message.msgid, message.symbol, message.old_names
    )
    self._messages_definitions[message.msgid] = message
    self._msgs_by_category[message.msgid[0]].append(message.msgid)