https://qooah.com/2012/05/25/android5-0-%e6%9c%80%e5%bf%ab-11%e6%9c%88%e9%9d%a2%e4%b8%96%ef%bc%8c%e6%96%b0%e4%b8%80%e4%bb%a3-nexus-%e5%b0%87%e9%a0%90%e8%bc%89-jelly-bean-%e7%b3%bb%e7%b5%b1/