export declare class Heap<T> {
    _items: T[];
    _size: number;
    _comparator: (a: T, b: T) => boolean;
    constructor(items: T[], comparator?: (a: T, b: T) => boolean);
    empty(): boolean;
    pop(): T;
    push(item: T): void;
    size(): number;
    peek(): T;
}