export type ObserverCallback<K, V> = (operation: 'add' | 'delete' | 'update', key: K, value: V) => void;
export declare class ObserverMap<K extends string | number | symbol, V> {
    private _map;
    private _observers;
    constructor(entries?: readonly (readonly [K, V])[] | null);
    private notifyObservers;
    observe(callback: ObserverCallback<K, V>): void;
    unobserve(callback: ObserverCallback<K, V>): void;
    get(key: K): V | undefined;
    set(key: K, value: V): this;
    has(key: K): boolean;
    delete(key: K): boolean;
    clear(): void;
    get size(): number;
    keys(): IterableIterator<K>;
    values(): IterableIterator<V>;
    entries(): IterableIterator<[K, V]>;
    forEach(callbackfn: (value: V, key: K, map: Map<K, V>) => void, thisArg?: any): void;
}