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