private static <K, V> @Nullable FileBasedIndexExtension<K, V> findIndexExtension(@NotNull ID<K, V> id) {
    for (FileBasedIndexExtension<?, ?> extension : FileBasedIndexExtension.EXTENSION_POINT_NAME.getExtensionList()) {
      if (extension.getName() == id) {
        //noinspection unchecked
        return (FileBasedIndexExtension<K, V>)extension;
      }
    }
    return null;
  }
private static <K, V> @Nullable FileBasedIndexExtension<K, V> findIndexExtension(@NotNull ID<K, V> id)