def test_nonIntegerFDSVariable(self):
        """
        If the I{LISTEN_FDS} environment variable is set to a string that cannot
        be parsed as an integer, no inherited descriptors are reported.
        """
        fakeEnvironment = self.initializeEnvironment("hello, world", os.getpid())
        sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
        self.assertEqual([], sddaemon.inheritedDescriptors())

        If the I{LISTEN_FDS} environment variable is set to a string that cannot
        be parsed as an integer, no inherited descriptors are reported.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_systemd.py