internal static void SetImage (this CALayer layer, Xwt.Drawing.Image xwtImage, nfloat scale)
{
var image = xwtImage.ToNSImage ();
layer.ContentsScale = scale;
var layerContents = image.GetLayerContentsForContentsScale (layer.ContentsScale);
void_objc_msgSend_IntPtr (layer.Handle, setContentsSelector, layerContents.Handle);
layer.Bounds = new CGRect (0, 0, image.Size.Width, image.Size.Height);
}