docs: public static String getString(int handle, String key) {
  
          ResourceBundle bundle;
          String         s;
  
          synchronized (mutex) {
              if (handle < 0 || handle >= bundleList.size() || key == null) {
                  bundle = null;
              } else {
                  bundle = (ResourceBundle) bundleList.get(handle);
              }
          }
  
          if (bundle == null) {
              s = null;
          } else {
              try {
                  s = bundle.getString(key);
              } catch (Exception e) {
                  s = null;
              }
          }
  
          return s;
      }