export declare function replaceEmpty(s: string): string;
export declare function createBidirectionalMapping<A extends object, B extends object>(isA: (v: A | B) => boolean): {
    set: {
        (key: A, value: B): void;
        (key: B, value: A): void;
    };
    get: {
        (key: A): B;
        (key: B): A;
    };
    remove: (key: A | B) => void;
};