interface Event {

    // FIXME: second parameter: 'optional EventInit eventInitDict = {}'
    constructor(DOMString type);

    readonly attribute DOMString type;
    readonly attribute EventTarget? target;
    readonly attribute EventTarget? srcTarget;
    readonly attribute EventTarget? currentTarget;

    readonly attribute unsigned short eventPhase;

    undefined stopPropagation();
    attribute boolean cancelBubble;
    undefined stopImmediatePropagation();

    readonly attribute boolean bubbles;
    readonly attribute boolean cancelable;
    attribute boolean returnValue;
    undefined preventDefault();
    readonly attribute boolean defaultPrevented;
    readonly attribute boolean composed;

    readonly attribute boolean isTrusted;

    undefined initEvent(DOMString type, optional boolean bubbles = false, optional boolean cancelable = false);

};