'A TCP strports description may omit I{timeout} or I{bindAddress} to
allow the default to be used.'

def test_tcpDefaults(self):

    reactor = object()
    client = endpoints.clientFromString(reactor, 'tcp:host=example.com:port=1234')
    self.assertEqual(client._timeout, 30)
    self.assertIsNone(client._bindAddress)
