/**
 * Checks whether a value is null or undefined
 * @param {unknown} value - The value to check
 * @returns {boolean} True if the value is null or undefined
 * @example
 * isNullish(null); // true
 * isNullish(undefined); // true
 * isNullish(0); // false
 * isNullish(""); // false
 */
export declare const isNullish: (value: unknown) => value is null | undefined;