[Exposed=(Window,Worker)]
interface IDBKeyRange {
    [FIXME] readonly attribute any lower;
    [FIXME] readonly attribute any upper;
    [FIXME] readonly attribute boolean lowerOpen;
    [FIXME] readonly attribute boolean upperOpen;

    [FIXME, NewObject] static IDBKeyRange only(any value);
    [FIXME, NewObject] static IDBKeyRange lowerBound(any lower, optional boolean open = false);
    [FIXME, NewObject] static IDBKeyRange upperBound(any upper, optional boolean open = false);
    [FIXME, NewObject] static IDBKeyRange bound(any lower, any upper, optional boolean lowerOpen = false, optional boolean upperOpen = false);

    [FIXME] boolean includes(any key);
};