Ionic2 Contacts

This unofficial link shows the use of the Contacts class. Unfortunately, it isn’t working (at least on iOS). As I mentioned already this link is not available directly through the web site so I am asking myself if it should work at all?

Ionic Version: 2.0.0-alpha.42
Ionic CLI Version: 2.0.0-alpha.25
Ionic App Lib Version: 2.0.0-alpha.24