def METHOD_NAME(self):
    if NON_EXISTING_RESOLVABLE:
        raise unittest.SkipTest("Non-existing hosts are resolvable")
    url = "www.somedomainthatdoesntexi.st"
    errcode, out, err = yield self.execute([url, "-c", "item"], check_code=False)
    self.assertEqual(errcode, 1, out or err)
    self.assertIn(b"DNS lookup failed", err)