def pulse(self):
        """Close down any file tranfer sessions that have been open for too long."""
        current_time = time.time()
        for session in self.transfer_sessions:
            start_time, conn = self.transfer_sessions[session]
            if (current_time - start_time) > self.max_transfer_lifetime:
                message = '{} session on port {} timed out'
                self.transferComplete(session, message.format(session, conn.getHost().port))
        if self.transfer_sessions:
            reactor.callLater(self.check_alive_period, self.pulse)
dataset/ETHPy150Open ARM-software/workload-automation/wlauto/external/daq_server/src/daqpower/server.py/DaqFactory.pulse/original