https://naiwaen.debuggingsoft.com/2020/03/db2-%e0%b8%9b%e0%b8%a3%e0%b8%b0%e0%b9%80%e0%b8%a0%e0%b8%97%e0%b8%82%e0%b8%ad%e0%b8%87-license/