var mapView = args.object;
                var marker = new GoogleMaps.Marker();
                marker.position = GoogleMaps.Position.positionFromLatLng(36.799441, 10.178554);
                marker.title = "Tunis";
                marker.snippet = "Tunisia";
                marker.userData = {index: -1};


                let imgSrc = new ImageSource();
                imgSrc.fromBase64("iVBORw0KGgoAAAANSU.......kJggg==")

                let image = new Image();
                image.imageSource = imgSrc;
                marker.icon = image;

                mapView.addMarker(marker);