Binding.IndexerName and Binding.ProvideValue in Xamarin Forms

Hey,

I am trying to implement the answer in this so question: http://stackoverflow.com/questions/40554561/re-evaluate-all-values-in-xaml-page-calculated-by-a-markup-extension/40567656#40567656

The problem is, that in xamarin forms 2 ingredients do not exist (or I have not found them yet):

• Binding.IndexerName
• Binding.ProvideValue()

Do these simply not exist in Xamarin forms? Can I somehow "emulate" them?

Thanks!
Nathan