/**
 * It register the hexadecimal extension to the Faker instance.
 *
 * @param fake Faker instance
 *
 * @example
 * ```ts
 * import fake from '@micra/faker';
 * import {hexadecimal} from '@micra/faker/extensions/hexadecimal';
 *
 * fake.extend({hexadecimal});
 * ```
 */
export declare function hexadecimal(fake: Faker.Instance): (length?: number) => string;