'If a non-quiescent connection is put back in the cache, an error is
logged.'

def test_putNotQuiescent(self):

    protocol = StubHTTPProtocol()
    self.assertEqual(protocol.state, 'QUIESCENT')
    protocol.state = 'NOTQUIESCENT'
    self.pool._putConnection(('http', 'example.com', 80), protocol)
    (exc,) = self.flushLoggedErrors(RuntimeError)
    self.assertEqual(exc.value.args[0], 'BUG:    Non-quiescent    protocol    added    to    connection    pool.')
    self.assertIdentical(None, self.pool._connections.get(('http', 'example.com', 80)))
