docs: private void choose(String argument, String desc, Chooser chooser) {
          StringTokenizer tok = new StringTokenizer(argument, ",");
          while (tok.hasMoreTokens()) {
              String what = tok.nextToken().trim();
              if (!what.startsWith("+") && !what.startsWith("-")) {
                  throw new IllegalArgumentException(desc + " must start with " + "\"+\" or \"-\" (saw " + what + ")");
              }
              boolean enabled = what.startsWith("+");
              chooser.choose(enabled, what.substring(1));
          }
      }