public void ReorderAllColumns(List <string> keys) { if (!Cols.All(keys.Contains)) { string message = String.Format("ReorderAllColumns: keys({0}) to reorder are not the same as CSVData ({1})", String.Join(",", keys), String.Join(",", Cols)); throw new ArgumentOutOfRangeException(nameof(keys), message); } else { ReorderColumns(keys); } }