public virtual bool IsDiffFromPivot() { if (Bands.Any(band => band.IsDiffFromPivot())) { return(true); } foreach (var column in Columns) { if (column.IsAggregate) { if (!column.IsToDelete) { return(true); } } else { if (column.IsDiffFromPivot()) { return(true); } } } return(false); }