public static @NotNull Map<VirtualFile, VcsLogIndexer> getAvailableIndexers(@NotNull Map<VirtualFile, VcsLogProvider> providers) {
    Map<VirtualFile, VcsLogIndexer> indexers = new LinkedHashMap<>();
    for (Map.Entry<VirtualFile, VcsLogProvider> entry : providers.entrySet()) {
      VirtualFile root = entry.getKey();
      VcsLogProvider provider = entry.getValue();
      if (VcsLogProperties.SUPPORTS_INDEXING.getOrDefault(provider) && provider instanceof VcsIndexableLogProvider) {
        indexers.put(root, ((VcsIndexableLogProvider)provider).getIndexer());
      }
    }
    return indexers;
  }
public static @NotNull Map<VirtualFile, VcsLogIndexer> getAvailableIndexers(@NotNull Map<VirtualFile, VcsLogProvider> providers)