code: public static void setPasswordAuthenticator() {
      SecurityManager security = System.getSecurityManager();
      if (security != null) {
        try {
          security.checkPermission(new NetPermission("setDefaultAuthenticator"));
          Authenticator.setDefault(new PasswordAuthenticator());
        } catch (SecurityException e) {
          // ignore, but the feature to use user:password in the URL cannot be used now,
          // see https://github.com/languagetool-org/languagetool/issues/255
        }
      } else {
        Authenticator.setDefault(new PasswordAuthenticator());
      }
    }
docs: Calls {@code Authenticator.setDefault()} with a password
  authenticator so that it's possible to use URLs of the
  format {@code http://username:password@server} when loading XML files.
  If the password manager doesn't allow calling {@code Authenticator.setDefault()},
  this will be silently ignored and the feature of using these URLs
  will not be available.
  @since 3.0