@NotNull
  private Collection<VcsRootError> calcErrors(@NotNull Collection<VcsRoot> detectedRoots) {
    List<VcsDirectoryMapping> mappings = myVcsManager.getDirectoryMappings();
    Collection<VcsRootError> errors = new ArrayList<>();
    errors.addAll(findExtraMappings(mappings));
    errors.addAll(findUnregisteredRoots(mappings, detectedRoots));
    return errors;
  }
@NotNull
  private Collection<VcsRootError> calcErrors(@NotNull Collection<VcsRoot> detectedRoots)