/**
 *
 * @param {T} obj
 * @param {(obj: T) => R} fn
 * @param {R} defaultValue
 * @param {boolean} excludeNull
 * @returns {R}
 */
export declare function get<T, R>(obj: T, fn: (obj: T) => R, defaultValue?: R, excludeNull?: boolean): R;
/**
 *
 * @param {T} obj
 * @param {(o: T) => R} getFn
 * @returns {any}
 */
export declare function has<T, R>(obj: T, getFn: (o: T) => R): boolean;