// https://html.spec.whatwg.org/multipage/canvas.html#canvasshadowstyles
interface mixin CanvasShadowStyles {
    // shadows
    attribute unrestricted double shadowOffsetX; // (default 0)
    attribute unrestricted double shadowOffsetY; // (default 0)
    attribute unrestricted double shadowBlur; // (default 0)
    attribute DOMString shadowColor; // (default transparent black)
};