def METHOD_NAME(self, parent=QtCore.QModelIndex()):
    sourceParent = self.mapToSource(parent)
    source_rows = self.sourceModel().METHOD_NAME(parent=sourceParent)
    rows = math.ceil(source_rows / self._nd)
    # print('StripeProxyModel.rowCount(): %r %r' % (source_rows, rows))
    return int(rows)