if (ip instanceof Inet6Address) {
      return "[" + toAddrString(ip) + "]";
    }
    return toAddrString(ip);
  }

  /**
   * Returns an InetAddress representing the literal IPv4 or IPv6 host portion of a URL, encoded in
   * the format specified by RFC 3986 section 3.2.2.
   *
   * <p>This method is similar to {@link InetAddresses#forString(String)}, however, it requires that

   *
   * @since 6.0
   */
  public boolean hasPublicSuffix() {
    return publicSuffixIndex() != NO_SUFFIX_FOUND;
  }

  /**
   * Returns the {@linkplain #isPublicSuffix() public suffix} portion of the domain name, or {@code
   * null} if no public suffix is present.
   *
   * @since 6.0
   */
  @CheckForNull
  public InternetDomainName publicSuffix() {

    if (elements instanceof ImmutableCollection) {
      /*
       * TODO: When given an ImmutableList that's a sublist, copy the referenced
       * portion of the array into a new array to save space?
       */
      @SuppressWarnings("unchecked") // all supported methods are covariant
      ImmutableCollection<E> list = (ImmutableCollection<E>) elements;