public static TransformableUnboundColumnBuilder <RecordT, bool> TransformableDefault <RecordT>(
     this ValueContainingUnboundColumnBuilder <RecordT, bool> self,
     params GrouperDefOrAggregatorDef <bool>[] additionalGrouperOrAggr) where RecordT : new()
 {
     return(self.Transformable(x => DataGridColumnController.ForBool(x, additionalGrouperOrAggr)));
 }