def _on_trigger(self, my_task):
for task in my_task.workflow.task_tree._find_any(self):<EOL><INDENT>if task.thread_id != my_task.thread_id:<EOL><INDENT>continue<EOL><DEDENT>self._do_join(task)<EOL><DEDENT>
May be called to fire the Join before the incoming branches are
completed.