Swift 3：AppDelegate不符合协议GIDSignInDelegate

现在我正在尝试实施Google登录.
我这样跟着：
https://developers.google.com/identity/sign-in/ios/sign-in?ver=swift

但我在AppDelegate.swift中遇到错误：

class AppDelegate: UIResponder,UIApplicationDelegate,GIDSignInDelegate 
....

错误：

Type ‘AppDelegate’ does not conform to protocol ‘GIDSignInDelegate’

帮我.

您需要在AppDelegate中实现GIDSignInDelegate的这两种方法.

func sign(_ signIn: GIDSignIn!,diddisconnectWith user: GIDGoogleUser!,withError error: Error!) {

}

func sign(_ signIn: GIDSignIn!,didSignInFor user: GIDGoogleUser!,withError error: Error!) {

}