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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 is_expired(self):
 """ Indicates if connection has expired. """

        if time.time() - self.last_ping > HB_PING_TIME:
            self.ping()

        return (time.time() - self.last_pong) > HB_PING_TIME + HB_PONG_TIME