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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 start_user_socket(self, callback):
 """Start a websocket for user data https://github.com/binance-exchange/binance-official-api-docs/blob/master/user-data-stream.md :param callback: callback function to handle messages :type callback: function :returns: connection key string if successful, False otherwise Message Format - see Binance API docs for all types """

        # Get the user listen key
        user_listen_key = self._client.stream_get_listen_key()
        # and start the socket with this specific key
        conn_key = self._start_user_socket(user_listen_key, callback)
        return conn_key