@Override
  public FileDifferenceModel getDifferenceModel() {
    return new SelectionDifferenceModel(myProject,
                                        myGateway,
                                        getCalculator(),
                                        getLeftRevision(),
                                        getRightRevision(),
                                        myFrom,
                                        myTo,
                                        isCurrentRevisionSelected());
  }
@Override
  public FileDifferenceModel getDifferenceModel()