def test_contextManager(self):
        """
        When used as a context manager, a L{NonePIDFile} doesn't raise, despite
        not existing.
        """
        pidFile = NonePIDFile()

        with pidFile:
            pass

        When used as a context manager, a L{NonePIDFile} doesn't raise, despite
        not existing.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/application/runner/test/test_pidfile.py