* @throws IllegalArgumentException if {@code host} contains a port number, or {@code port} is out
   *     of range.
   */
  public static HostAndPort fromParts(String host, int port) {
    checkArgument(isValidPort(port), "Port out of range: %s", port);
    HostAndPort parsedHost = fromString(host);
    checkArgument(!parsedHost.hasPort(), "Host has a port: %s", host);