export interface Comparator<T> {
    (o1: T, o2: T): number;
}

let comparator: Comparator<number> = (n1: number, n2: number): number => {
    return n1 - n2;
};
let treeMap: SortedMap<number, string> = new TreeMap<number, string>(comparator);

default Comparator<T> reversed() {
    return Collections.reverseOrder(this);
}