throw new IllegalArgumentException();
throw new IllegalArgumentException("Bad port number: " + port);
  public InetSocketAddress(String hostname, int port)    throws IllegalArgumentException  {    if (port < 0 || port > 65535)      throw new IllegalArgumentException();    this.port = port;    this.hostname = hostname;    try      {        this.addr = InetAddress.getByName(hostname);      }    catch (Exception e) // UnknownHostException, SecurityException      {        this.addr = null;      }  }