def test_listWithInvalidStat(self):
        """
        Querying an invalid stat should result to a C{AttributeError}.
        """
        self.createDirectory('ned')
        d = self.shell.list(('.',), ('size', 'whateverstat',))
        return self.assertFailure(d, AttributeError)

        Querying an invalid stat should result to a C{AttributeError}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_ftp.py