export declare class BetterMap<K, V> extends Map<K, V> {
    getOrThrow(key: K): V;
    getOrSet(key: K, factory: () => V): V;
    map<T>(fn: (value: V, key: K) => T): BetterMap<K, T>;
    reduce<T>(fn: (acc: T, value: V, key: K) => T, initial: T): T;
    toObject(): Record<string, V>;
}
export declare class DefaultMap<K, V> extends BetterMap<K, V> {
    private readonly factory;
    constructor(factory: () => V, initial?: [K, V][]);
    get(key: K): V;
}