def test_daemonPIDFile(self):
        pidfile = self.mktemp()
        with AlternateReactor(FakeDaemonizingReactor()):
            self.runner.setupEnvironment(None, ".", False, None, pidfile)
        with open(pidfile, 'rb') as f:
            pid = int(f.read())
        self.assertEqual(pid, self.pid + 1)
L{UnixApplicationRunner.setupEnvironment} writes the daemonized
dataset/ETHPy150Open twisted/twisted/twisted/test/test_twistd.py/UnixApplicationRunnerSetupEnvironmentTests.test_daemonPIDFile