Xamarin.Forms creating an Android Native Listview with pull to refresh

I've pulled down the "Working with ListView Native Layouts" projects (https://developer.xamarin.com/samples/xamarin-forms/WorkingWithListviewNative/)

and I'm building an app that has a similar structure to the ListView example in folder D. Now i'm trying to add Pull to refresh to this example, but i'm having a hard time with it. How would i go about this?

The sample implementation is loaded once at the begining from DataSource2.cs, is there anyway to get new data in without directly loading nativeListView2.Items?