public sealed class SurfaceZsResult 

var geometry = await QueuedTask.Run<Geometry>(() =>
{
  Geometry mapCentergeometry = MapView.Active.Map.CalculateFullExtent().Center;
  return mapCentergeometry;
});
//Pass any Geometry type to GetZsFromSurfaceAsync
var surfaceZResult = await MapView.Active.Map.GetZsFromSurfaceAsync(geometry);
return surfaceZResult;