def serialize_task_id(self):
        """
        Create a unique identifier for the current location within the task.

        The format is C{b"<task_uuid>@<task_level>"}.

        @return: L{bytes} encoding the current location within the task.
        """
        return "{}@{}".format(
            self._identification[TASK_UUID_FIELD],
            self._nextTaskLevel().toString()).encode("ascii")
Create a unique identifier for the current location within the task.

        The format is C{b"<task_uuid>@<task_level>"}.

        @return: L{bytes} encoding the current location within the task.