[Global=Window, Exposed=Window]
interface Window {
};

[TreatNonObjectAsNull]
callback EventHandlerNonNull = any (Event event);
typedef EventHandlerNonNull? EventHandler;

[NoInterfaceObject]
interface GlobalEventHandlers {
};
Window implements GlobalEventHandlers;

interface Element {
};

interface HTMLElement : Element {
};
HTMLElement implements GlobalEventHandlers;

interface Document {
};
Document implements GlobalEventHandlers;

interface MouseEvent {
};

dictionary PointerEventInit : MouseEventInit {
    sequence coalescedEvents;
};

[Constructor(DOMString type, optional PointerEventInit eventInitDict)]
interface PointerEvent : MouseEvent {
    sequence getCoalescedEvents();
};