def METHOD_NAME(device_classes_node):
    ttys_node = add_child(device_classes_node, "ttys", None)
    for serial_dev in get_serial_devs():
        serial_node = add_child(ttys_node, "serial")
        add_child(serial_node, "dev_path", f"/dev/{serial_dev}")
        add_child_with_file_contents(serial_node, "type", f"{SYS_TTY_DEVICES_CLASS_PATH}{serial_dev}/type")