/**
 * A simple two-key map.
 */
export declare class TwoKeyMap<K1, K2, V> {
    private baseMap;
    forEach(op: (v: V) => void): void;
    has(key1: K1, key2: K2): boolean;
    getIfOnly(key1: K1): readonly [K2, V] | undefined;
    get(key1: K1, key2: K2): V | undefined;
    set(key1: K1, key2: K2, value: V): void;
}
/**
 * If the predicate returns a value other than undefined,
 * that value is returned. It combines the .find() and
 * .map() APIs for convenience.
 *
 * @param arr
 * @param predicate
 */
export declare function findMap<T, K>(arr: T[], predicate: (p: T) => K | undefined): K | undefined;