async def METHOD_NAME(self):
    router = Router()
    observer = router.message
    observer.register(my_handler, MyFilter1(test="ok"))
    message = Message(
        message_id=42,
        date=datetime.datetime.now(),
        text="test",
        chat=Chat(id=42, type="private"),
        from_user=User(id=42, is_bot=False, first_name="Test"),
    )
    results = await observer.trigger(message)
    assert results is message