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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(self):
 """Start thread."""

        if not self._thread:
            logging.info("Starting asterisk mbox thread")
            # Ensure signal queue is empty
            try:
                while True:
                    self.signal.get(False)
            except queue.Empty:
                pass
            self._thread = threading.Thread(target=self._loop)
            self._thread.setDaemon(True)
            self._thread.start()