private VcsRevisionNumber fromDiffProvider(@NotNull VirtualFile vf) {
    final VcsRoot vcsRoot = myVcsManager.getVcsRootObjectFor(vf);
    DiffProvider diffProvider;
    if (vcsRoot != null && vcsRoot.getVcs() != null && (diffProvider = vcsRoot.getVcs().getDiffProvider()) != null) {
      return diffProvider.getCurrentRevision(vf);
    }
    return null;
  }
private VcsRevisionNumber fromDiffProvider(@NotNull VirtualFile vf)