def getDaemon(self, start, count):
        """
        Create a new L{ListenFDs} instance, initialized with a fake environment
        dictionary which will be set up as systemd would have set it up if
        C{count} descriptors were being inherited.  The descriptors will also
        start at C{start}.
        """
        fakeEnvironment = self.initializeEnvironment(count, os.getpid())
        return ListenFDs.fromEnvironment(environ=fakeEnvironment, start=start)

        Create a new L{ListenFDs} instance, initialized with a fake environment
        dictionary which will be set up as systemd would have set it up if
        C{count} descriptors were being inherited.  The descriptors will also
        start at C{start}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_systemd.py