@Override
  public <K> boolean processAllKeys(@NotNull ID<K, ?> indexId,
                                    @NotNull Processor<? super K> processor,
                                    @NotNull GlobalSearchScope scope,
                                    @Nullable IdFilter idFilter) {
    Boolean scanResult = FileBasedIndexScanUtil.processAllKeys(indexId, processor, scope, idFilter);
    if (scanResult != null) return scanResult;
    return super.processAllKeys(indexId, processor, scope, idFilter);
  }
@Override
  public <K> boolean processAllKeys(@NotNull ID<K, ?> indexId,
                                    @NotNull Processor<? super K> processor,
                                    @NotNull GlobalSearchScope scope,
                                    @Nullable IdFilter idFilter)