好像写作文啊，好陌生的感觉。
下面插入一段代码，看看格式：
[UIView animateWithDuration:1.0 animations:^{
//do something
} completion:^(BOOL finished) {
//do something
}];
下面是链接的格式：
var langName: String = "Swift" // this is a swift code that i wrote, i just want to add a long length string in one line to test
