import type { IsISBNOptions } from '../types/index';
/**
 * Check if the string is a valid ISBN (International Standard Book Number)
 *
 * @param isbn - The string to check
 * @param options - Options object that specifies ISBN version to validate against
 * @returns True if the string is a valid ISBN, false otherwise
 */
export default function isISBN(isbn: string, options?: IsISBNOptions | string | number): boolean;