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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def subscribe(ws):
 """WebSocket endpoint, used for liveupdates"""

    while ws is not None:
        gevent.sleep(0.1)
        try:
            message = ws.receive()  # expect function name to subscribe to
            if message:
                stream.register(ws, message)
        except WebSocketError:
            ws = None