declare module "punycode.js" {
  export function decode(input: string): string;
  export function encode(input: string): string;
  export function toUnicode(input: string): string;
  export function toASCII(input: string): string;

  export namespace ucs2 {
    function decode(string: string): number[];
    function encode(array: readonly number[]): string;
  }

  export const version: string;
}