@Override
  public VcsHistorySession createSessionFor(FilePath filePath) {
    final VirtualFile vcsRoot = VcsUtil.getVcsRootFor(myProject, filePath);
    if (vcsRoot == null) {
      return null;
    }
    final List<VcsFileRevision> revisions = new ArrayList<>(getHistory(filePath, vcsRoot, myProject));
    return createAppendableSession(vcsRoot, filePath, revisions,
                                   revisions.isEmpty() ? null : requireNonNull(getFirstItem(revisions)).getRevisionNumber());
  }
@Override
  public VcsHistorySession createSessionFor(FilePath filePath)