class URL implements Serializable {

  public String getAuthority() {
    if ((username == null || username.length() == 0)
      && (password == null || password.length() == 0)) {
      return null;
    }
    return (username == null ? "" : username)
      + ":" + (password == null ? "" : password);
  }

  protected  URL();
  public  URL(String protocol, String host, int port);
  public  URL(String protocol, String host, int port, String[] pairs);
  public  URL(String protocol, String host, int port, Map<String, String> parameters);
  public  URL(String protocol, String host, int port, String path);
  public  URL(String protocol, String host, int port, String path, String... pairs);
  public  URL(String protocol, String host, int port, String path, Map<String, String> parameters);
  public  URL(String protocol, String username, String password,
             String host, int port, String path);
  public  URL(String protocol, String username, String password,
             String host, int port, String path, String... pairs);
  public  URL(String protocol, String username, String password,
             String host, int port, String path, Map<String, String> parameters);

}