/**
 * Checks if `test` is nil (null or undefined).
 *
 * @param {*} test The value to check.
 * @returns {boolean} Returns `true` if `test` is nil, else `false`.
 * @example
 *
 *    isNil(undefined); //=> true
 *    isNil(null);      //=> true
 *    isNil('');        //=> false
 *    isNil(5);         //=> false
 */
export declare const isNil: (test: any) => test is void;
export default isNil;