def test_killRequestedWithoutPIDFile(self):
        """
        L{Runner.killIfRequested} when C{kill} is true but C{pidFile} is
        L{nonePIDFile} exits with L{ExitStatus.EX_USAGE} and the expected
        message; and also doesn't indiscriminately murder anyone.
        """
        runner = Runner(reactor=MemoryReactor(), kill=True)
        runner.killIfRequested()

        self.assertEqual(self.kill.calls, [])
        self.assertEqual(self.exit.status, ExitStatus.EX_USAGE)
        self.assertEqual(self.exit.message, "No PID file specified.")

        L{Runner.killIfRequested} when C{kill} is true but C{pidFile} is
        L{nonePIDFile} exits with L{ExitStatus.EX_USAGE} and the expected
        message; and also doesn't indiscriminately murder anyone.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/application/runner/test/test_runner.py