Map renderer in iOS

Hello i've the last version of all the packages (forms 1.2.2.6243 and maps 1.2.2.6243) and i need to create a map renderer (as i have already done in android) to handle the click on a pin and be able to open a detail view.

When i try to inherit from Xamarin.Forms.Maps.iOS.MapRenderer i get this error: Error CS0122: `Xamarin.Forms.Maps.iOS.MapRenderer' is inaccessible due to its protection level (CS0122) (AnagrafeCaninaMobileFORMS.iOS)

probably because the constructor is private...

any idea about how to sort this problem out?

Thanks

Alessandro Facchini