def __init__(self, request_id, topic, on_reply, handler):
        Request.__init__(self, request_id, on_reply)
        self.topic = topic
        self.handler = handler
:param request_id: The WAMP request ID.
dataset/ETHPy150Open crossbario/autobahn-python/autobahn/wamp/request.py/SubscribeRequest.__init__