/**
 * Checks if the provided link is an external Url.
 *
 * Inspired on the Frontity implementation
 *
 * @param link The link Url.
 *
 * @see https://github.com/frontity/frontity/blob/dev/packages/components/link/utils.ts
 *
 * @returns True if the link is an external Url.
 */
export declare function isExternalUrl(link: string): boolean;