code: public static List<LanguageExtension> findAll(Collection<? extends Extension> extensions)
      {
          List<LanguageExtension> result = new ArrayList<LanguageExtension>();
          for (Extension extension : extensions)
          {
              if (LANGUAGE_EXTENSION_ID == extension.getId())
                  result.add((LanguageExtension)extension);
          }
          return result;
      }
docs: Returns all LanguageExtension found in the given collection of extensions,
  or an empty list if the extension collection does not contain LanguageExtensions.