/**
 * Checks if the string is an IP (version 4 or 6).
 * If given value is not a string, then it returns false.
 *
 * @param value The value being checked.
 * @returns  True if the string is an IP (version 4 or 6), false otherwise.
 */
export declare function isIP(value: string, version?: "4" | "6"): boolean;