
declare module "tty" {
  /**
   * The `tty.isatty()` method returns `true` if the given `fd` is associated with
   * a TTY and `false` if it is not, including whenever `fd` is not a non-negative
   * integer.
   * @since v0.5.8
   * @param fd A numeric file descriptor
   */
  function isatty(fd: number): boolean;
}