/**
 * ES6 Map 的部分实现
 */
export declare class Map<KeyType, ValueType> {
    private _keys;
    private _values;
    set(key: KeyType, value: ValueType): void;
    get(key: KeyType): ValueType | undefined;
    has(key: KeyType): boolean;
    clear(): void;
    keys(): KeyType[];
    values(): ValueType[];
}
export declare function increase<T>(map: Map<T, any>, key: T): any;
export declare function decrease<T>(map: Map<T, any>, key: T): number;