def test_idempotentChallenge(self):
        c = CramMD5Credentials()
        chal = c.getChallenge()
        self.assertEqual(chal, c.getChallenge())
The same L{CramMD5Credentials} will always provide the same challenge,
dataset/ETHPy150Open twisted/twisted/twisted/cred/test/test_cramauth.py/CramMD5CredentialsTests.test_idempotentChallenge