def test_mismatchedPID(self):
        """
        If the current process PID does not match the PID in the environment, no
        inherited descriptors are reported.
        """
        fakeEnvironment = self.initializeEnvironment(3, os.getpid() + 1)
        sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
        self.assertEqual([], sddaemon.inheritedDescriptors())

        If the current process PID does not match the PID in the environment, no
        inherited descriptors are reported.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_systemd.py