public static extern ILeafletMarker Marker(ILeafletLatLng latLng, LeafletMarkerOptions options = null);
public static extern ILeafletCircle Circle(ILeafletLatLng latLng, LeafletCircleOptions options = null);
public static extern ILeafletLatLngBounds LatLngBounds(ILeafletLatLng corner1, ILeafletLatLng corner2);