https://qooah.com/2011/04/29/motorola%e3%80%8c%e6%98%8e%e3%80%8d%e7%b3%bb%e5%88%97%e6%90%ad%e4%b8%8aandroid%e5%86%8d%e7%8f%be%e6%b8%af%e5%8f%b0-%ef%bc%8d-a1680/