code: public void setSetting(int setting) throws CDKException {
          if (setting < settings.size() + 1 && setting > 0) {
              this.setting = (String) settings.get(setting - 1);
          } else {
              throw new CDKException("Setting " + setting + " does not exist.");
          }
      }
docs: Sets the setting for a certain question. It will throw
  a CDKException when the setting is not valid. The first setting is
  setting 1.