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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_handshake(self, timeout):
 """ Tells `Packetizer` that the handshake process started. Starts a book keeping timer that can signal a timeout in the handshake process. :param float timeout: amount of seconds to wait before timing out """

        if not self.__timer:
            self.__timer = threading.Timer(float(timeout), self.read_timer)
            self.__timer.start()