def test_errorLogWithInnerFrameRef(self):
        """
        Same as L{test_errorLog}, but with an inner frame.
        """
        def _subErrorLogWithInnerFrameRef():
            d = defer.Deferred()
            d.addCallback(lambda x: 1 // 0)
            d.callback(1)

        _subErrorLogWithInnerFrameRef()
        gc.collect()
        self._check()

        Same as L{test_errorLog}, but with an inner frame.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_defer.py