public @NotNull DiffContent getLeftDiffContent(@NotNull RevisionProcessingProgress p) {
    Entry leftEntry = getLeftEntry();
    if (leftEntry == null) return DiffContentFactory.getInstance().createEmpty();
    if (isLeftContentAvailable(p)) {
      DiffContent content = getReadOnlyLeftDiffContent(p);
      if (content != null) return content;
    }
    return DiffContentFactory.getInstance().create(LocalHistoryBundle.message("content.not.available"));
  }
public @NotNull DiffContent getLeftDiffContent(@NotNull RevisionProcessingProgress p)