docs: static List<File> listExtensionDirectories() {
          List<File> dirs = new ArrayList<File>();
          dirs.add(new File(CustomUtils.getInstallRoot(), USER_FEATURE_DIR)); // wlp/usr/extension
  
          for (ProductExtensionInfo info : ProductExtension.getProductExtensions()) {
              File extensionDir = new File(info.getLocation());
              if (!isAbsolute(extensionDir)) {
                  File parentDir = new File(CustomUtils.getInstallRoot()).getParentFile();
                  extensionDir = new File(parentDir, info.getLocation());
              }
              if (logger.isLoggable(Level.FINE)) {
                  logger.fine("The product extension directory : " + extensionDir);
              }
              dirs.add(extensionDir);
          }
          return dirs;
      }