'Like test_ciphers, but for the various MACs.'

def test_macs(self):

    deferreds = []
    for mac in (transport.SSHTransportBase.supportedMACs + ['none']):
        def setMAC(proto):
            proto.supportedMACs = [mac]
            return proto
        deferreds.append(self._runClientServer(setMAC))
    return defer.DeferredList(deferreds, fireOnOneErrback=True)
