declare class BetterMap<K, V> extends Map<K, V> {
    /**
     * @param getDefaultValue Return the value associated with the key.
     * If that value does not exist it sets the result of `getDefaultValue()` and returns that.
     */
    get: {
        (key: K): V | undefined;
        (key: K, getDefaultValue: () => V): V;
    };
}
declare class BetterWeakMap<K extends object | symbol, V> extends WeakMap<K, V> {
    /**
     * @param getDefaultValue Return the value associated with the key.
     * If that value does not exist it sets the result of `getDefaultValue()` and returns that.
     */
    get: {
        (key: K): V | undefined;
        (key: K, getDefaultValue: () => V): V;
    };
}
export { BetterMap, BetterWeakMap };