def test_success(self):
        with AlternateReactor(FakeDaemonizingReactor()):
            self.runner.postApplication()
        self.assertEqual(
            self.mockos.actions,
            [('chdir', '.'), ('umask', 0o077), ('fork', True), 'setsid',
             ('fork', True), ('write', -2, '0'), ('unlink', 'twistd.pid')])
        self.assertEqual(self.mockos.closed, [-3, -2])
When double fork succeeded in C{daemonize}, the child process writes
dataset/ETHPy150Open twisted/twisted/twisted/test/test_twistd.py/DaemonizeTests.test_success