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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 empty(self):
 """ Clear out the buffer and return all data that was in it. :return: any data that was in the buffer prior to clearing it out, as a `str` """

        self._lock.acquire()
        try:
            out = self._buffer_tobytes()
            del self._buffer[:]
            if (self._event is not None) and not self._closed:
                self._event.clear()
            return out
        finally:
            self._lock.release()