def test_accessNotFound(self):
        """
        access should fail on a resource that doesn't exist.
        """
        d = self.shell.access(('foo',))
        return self.assertFailure(d, ftp.FileNotFoundError)

        access should fail on a resource that doesn't exist.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_ftp.py