private async Task ShowPlaces()
{
// Find places in this category near the current location
List <Graphic> places = await _viewModel.FindPlaces(_deviceLocation);
// ** Better performance using AddRange **
// https://community.esri.com/community/developers/native-app-developers/arcgis-runtime-sdk-for-net/blog/2019/10/09/improve-performance-with-addrange
_placesGraphicsOverlay.Graphics.AddRange(places);
}