public class CIMMultipointGraphic : CIMShapeGraphic, System.ComponentModel.INotifyPropertyChanged, System.Xml.Serialization.IXmlSerializable  

//On the QueuedTask
//Place a multipoint graphic using the mapview extent geometry
var extent = MapView.Active.Extent;
//Contract the extent
var polygonEnv = extent.Expand(-100000, -90000, false);
//create a polygon using the envelope
var polygon = PolygonBuilderEx.CreatePolygon(polygonEnv);
//Create MultipPoints from the polygon
var multiPoints = MultipointBuilderEx.CreateMultipoint(polygon);
//specify a symbol
var point_symbol = SymbolFactory.Instance.ConstructPointSymbol(
                      ColorFactory.Instance.GreenRGB);

//create a CIMGraphic 
var graphic = new CIMMultipointGraphic
{
  Symbol = point_symbol.MakeSymbolReference(),
  Multipoint = multiPoints
};
graphicsLayer.AddElement(graphic);