How to use the sshuttle.sdnotify.send function in sshuttle

def test_notify_sendto_error(mock_get, mock_socket):
    message = sshuttle.sdnotify.ready()
    socket_path = '/run/valid_path'

    sock = Mock()
    sock.sendto.side_effect = socket.error('test error')
    mock_get.return_value = '/run/valid_path'
    mock_socket.return_value = sock

    assert not sshuttle.sdnotify.send(message)
    assert sock.sendto.mock_calls == [
        call(message, socket_path),
    ]

def test_notify(mock_get, mock_socket):
    messages = [sshuttle.sdnotify.ready(), sshuttle.sdnotify.status('Running')]
    socket_path = '/run/valid_path'

    sock = Mock()
    sock.sendto.return_value = 1
    mock_get.return_value = '/run/valid_path'
    mock_socket.return_value = sock

    assert sshuttle.sdnotify.send(*messages)
    assert sock.sendto.mock_calls == [
        call(b'\n'.join(messages), socket_path),
    ]

def test_notify_no_message(mock_get):
    mock_get.return_value = '/run/valid_path'
    assert not sshuttle.sdnotify.send()

# authentication at shutdown time - that cleanup is important!
        while 1:
            line = stdin.readline(128)
            if line.startswith('HOST '):
                (name, ip) = line[5:].strip().split(',', 1)
                hostmap[name] = ip
                debug2('firewall manager: setting up /etc/hosts.\n')
                rewrite_etc_hosts(hostmap, port_v6 or port_v4)
            elif line:
                if not method.firewall_command(line):
                    raise Fatal('firewall: expected command, got %r' % line)
            else:
                break
    finally:
        try:
            sdnotify.send(sdnotify.stop())
            debug1('firewall manager: undoing changes.\n')
        except BaseException:
            debug2('An error occurred, ignoring it.')

        try:
            if subnets_v6 or nslist_v6:
                debug2('firewall manager: undoing IPv6 changes.\n')
                method.restore_firewall(port_v6, socket.AF_INET6, udp, user)
        except BaseException:
            try:
                debug1("firewall manager: "
                       "Error trying to undo IPv6 firewall.\n")
                for line in traceback.format_exc().splitlines():
                    debug1("---> %s\n" % line)
            except BaseException:
                debug2('An error occurred, ignoring it.')