Possible bug in Image.IsLoading

Hi, I tried this in XF 1.5 and 2.x but I'm not able to reproduce this piece of code:

var image = new Image { 
  Source = new ImageLoader {
    Uri = new Uri ("http://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57723/globe_west_2048.jpg"),
    CachingEnabled = false,
  },
  WidthRequest = 200,
  HeightRequest = 200,
};

var indicator = new ActivityIndicator {Color = new Color (.5),};
indicator.SetBinding (ActivityIndicator.IsRunningProperty, "IsLoading");
indicator.BindingContext = image;

I found this in the official documentation of XF here but it seems to not working... ImageLoader is found only under "MonoTouch.Dialog.Utilities" but it is not what I'm looking for.