'If a L{client._RetryingHTTP11ClientProtocol} fails more than once on
an idempotent query before a response is received, it will not retry.'

def test_onlyRetryOnce(self):

    (d, protocols) = self.retryAttempt(True)
    self.assertEqual(len(protocols), 2)
    protocols[1].requests[0][1].errback(ResponseNeverReceived([]))
    self.assertEqual(len(protocols), 2)
    return self.assertFailure(d, ResponseNeverReceived)
