export interface LightMap<K, V> { [Symbol.toStringTag]: string; has(key: K): boolean; get(key: K): V | undefined; set(key: K, value: V): this; delete(key: K): boolean; keys(): Iterable<K>; } export declare class LightMapImpl<K, V> implements LightMap<K, V> { [Symbol.toStringTag]: string; private readonly record; constructor(); has(key: K): boolean; get(key: K): V | undefined; set(key: K, value: V): this; delete(key: K): boolean; keys(): Iterable<K>; } export declare const Polyfill: { new <K, V>(): LightMap<K, V>; };