code: static List<LaunchManifest.RequiredBundle> findExtensionBundles(String extension) throws IOException {
          // first, make the list of directories to look into.
          List<File> dirs = listToolExtensionDirectories(extension);
          List<LaunchManifest.RequiredBundle> list = findExtensionBundles(dirs);
          return list;
      }
docs: Find Required bundles from the manifest file which matches extension name..
  returns list of RequredBundle object, if there is none, return null.
  the directories which the code looks into are:
  1, wlp/bin/tools/extensions,
  2. wlp/usr/extension/bin/tools/extensions,
  3. all locations returned from ProductExtension.getProductExtensions() with /bin/tools/extensions