def METHOD_NAME(self, ac_id, msg):
    if ac_id not in self.aircrafts:
        self.add_new_aircraft(ac_id)
    aircraft = self.aircrafts[ac_id]
    if msg.name not in aircraft.messages:
        self.add_new_message(aircraft, msg.msg_class, msg.name)
    aircraft.messages_book.SetPageImage(aircraft.messages[msg.name].index, 1)
    self.aircrafts[ac_id].messages[msg.name].last_seen = time.time()
    for index in range(0, len(msg.fieldvalues)):
        aircraft.messages[msg.name].field_controls[index].SetLabel(str(msg.get_field(index)))