@Nullable
  private static Map<VcsRevisionNumber, Integer> computeLineNumbers(@NotNull FileAnnotation fileAnnotation) {
    final Map<VcsRevisionNumber, Integer> numbers = new HashMap<>();
    final List<VcsFileRevision> fileRevisionList = fileAnnotation.getRevisions();
    if (fileRevisionList != null) {
      int size = fileRevisionList.size();
      for (int i = 0; i < size; i++) {
        VcsFileRevision revision = fileRevisionList.get(i);
        final VcsRevisionNumber number = revision.getRevisionNumber();

        numbers.put(number, size - i);
      }
    }
    return numbers.size() < 2 ? null : numbers;
  }
@Nullable
  private static Map<VcsRevisionNumber, Integer> computeLineNumbers(@NotNull FileAnnotation fileAnnotation)