def test_init(self):
        """
        Test that SSHChannel initializes correctly.  localWindowSize defaults
        to 131072 (2**17) and localMaxPacket to 32768 (2**15) as reasonable
        defaults (what OpenSSH uses for those variables).

        The values in the second set of assertions are meaningless; they serve
        only to verify that the instance variables are assigned in the correct
        order.
        """
        c = channel.SSHChannel(conn=self.conn)
        self.assertEqual(c.localWindowSize, 131072)
        self.assertEqual(c.localWindowLeft, 131072)
        self.assertEqual(c.localMaxPacket, 32768)
        self.assertEqual(c.remoteWindowLeft, 0)
        self.assertEqual(c.remoteMaxPacket, 0)
        self.assertEqual(c.conn, self.conn)
        self.assertIsNone(c.data)
        self.assertIsNone(c.avatar)

        c2 = channel.SSHChannel(1, 2, 3, 4, 5, 6, 7)
        self.assertEqual(c2.localWindowSize, 1)
        self.assertEqual(c2.localWindowLeft, 1)
        self.assertEqual(c2.localMaxPacket, 2)
        self.assertEqual(c2.remoteWindowLeft, 3)
        self.assertEqual(c2.remoteMaxPacket, 4)
        self.assertEqual(c2.conn, 5)
        self.assertEqual(c2.data, 6)
        self.assertEqual(c2.avatar, 7)

        Test that SSHChannel initializes correctly.  localWindowSize defaults
        to 131072 (2**17) and localMaxPacket to 32768 (2**15) as reasonable
        defaults (what OpenSSH uses for those variables).

        The values in the second set of assertions are meaningless; they serve
        only to verify that the instance variables are assigned in the correct
        order.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_channel.py