Type Alias RealSvgRect

RealSvgRect: {
    height: number;
    width: number;
    x: number;
    y: number;
}

According to TypeScript SvgRect is an alias for DomRect. But that's not true. SvgRect is a class that has the following four properties. DomRect has a lot more properties. I can't find that documented anywhere, but that's what I see running Chrome.