@Nullable
  private static ContentRevision createRevision(@NotNull DiffContent content, @NotNull String title) {
    if (content instanceof EmptyContent) return null;
    if (content instanceof FileContent) {
      VirtualFile file = ((FileContent)content).getFile();
      if (file.isInLocalFileSystem()) {
        return new CurrentContentRevision(VcsUtil.getFilePath(file));
      }
    }
    if (content instanceof DocumentContent) {
      String text = ((DocumentContent)content).getDocument().getText();

      Pair<FilePath, VcsRevisionNumber> info = content.getUserData(DiffVcsDataKeys.REVISION_INFO);
      if (info != null) {
        return new SimpleContentRevision(text, info.first, info.second.asString());
      }

      return new SimpleContentRevision(text, guessFilePath(content, title), "");
    }
    throw new IllegalStateException(content.toString());
  }
@Nullable
  private static ContentRevision createRevision(@NotNull DiffContent content, @NotNull String title)