public void testFromParts() {
    HostAndPort hp = HostAndPort.fromParts("gmail.com", 81);
    assertEquals("gmail.com", hp.getHost());
    assertTrue(hp.hasPort());
    assertEquals(81, hp.getPort());

    assertThrows(IllegalArgumentException.class, () -> HostAndPort.fromParts("gmail.com:80", 81));

    assertThrows(IllegalArgumentException.class, () -> HostAndPort.fromParts("gmail.com", -1));
  }

  public void testFromHost() {

   * @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);