GoogleAuthUtil GoogleAuthUtil provides static utility methods to acquire and invalidate authentication tokens. 


GoogleAuthException GoogleAuthExceptions signal Google authentication errors. 
GooglePlayServicesAvailabilityException GooglePlayServicesAvailabilityExceptions are special instances of UserRecoverableAuthExceptions which are thrown when the expected Google Play services app is not available for some reason. 
UserRecoverableAuthException UserRecoverableAuthExceptions signal Google authentication errors that can be recovered with user action, such as a user login. 
UserRecoverableNotifiedException UserRecoverableNotifiedException signals that there was a Google authentication error which can be recovered with user action and has been handled by publishing a notification for the user to act on.