def test_compressions(self):
        """
        Like test_ciphers, but for the various compressions.
        """
        deferreds = []
        for compression in transport.SSHTransportBase.supportedCompressions:
            def setCompression(proto):
                proto.supportedCompressions = [compression]
                return proto
            deferreds.append(self._runClientServer(setCompression))
        return defer.DeferredList(deferreds, fireOnOneErrback=True)

        Like test_ciphers, but for the various compressions.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_transport.py