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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 startAlertListener(self, callback=None):
 """ Creates a websocket connection to the Plex Server to optionally recieve notifications. These often include messages from Plex about media scans as well as updates to currently running Transcode Sessions. NOTE: You need websocket-client installed in order to use this feature. >> pip install websocket-client Parameters: callback (func):
 Callback function to call on recieved messages. raises: :class:`plexapi.exception.Unsupported`: Websocket-client not installed. """

        notifier = AlertListener(self, callback)
        notifier.start()
        return notifier