@Override
  public @NotNull Collection<VcsRoot> detect(@Nullable VirtualFile startDir) {
    MAPPING_DETECTION_LOG.debug("VcsRootDetectorImpl.detect root", startDir);
    if (startDir == null || !startDir.isInLocalFileSystem()) return Collections.emptyList();
    return Collections.unmodifiableSet(scanForDirectory(startDir));
  }
@Override
  public @NotNull Collection<VcsRoot> detect(@Nullable VirtualFile startDir)