def test_connectionMade(self):
        """
        SSHSessionProcessProtocol.connectionMade() should check if there's a
        'buf' attribute on its session and write it to the transport if so.
        """
        self.session.buf = b'buffer'
        self.pp.connectionMade()
        self.assertEqual(self.transport.buf, b'buffer')

        SSHSessionProcessProtocol.connectionMade() should check if there's a
        'buf' attribute on its session and write it to the transport if so.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_session.py