def test_removePID(self):
        """
        L{UnixApplicationRunner.removePID} deletes the file the name of
        which is passed to it.
        """
        runner = UnixApplicationRunner({})
        path = self.mktemp()
        os.makedirs(path)
        pidfile = os.path.join(path, "foo.pid")
        open(pidfile, "w").close()
        runner.removePID(pidfile)
        self.assertFalse(os.path.exists(pidfile))

        L{UnixApplicationRunner.removePID} deletes the file the name of
        which is passed to it.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_twistd.py