asColumnGroup
As ColumnGroup
Creates a ColumnAccessor<DataRow<C>> from this. This is especially useful when you want to use ColumnGroup functions in the ColumnsSelectionDsl but your column type is not recognized as a ColumnGroup. If you're not sure whether a column is recognized as ColumnGroup or not, you can always call asColumnGroup and it will return the same type if it is already a ColumnGroup.
NOTE: This does not check whether the column is actually a ColumnGroup or not. It just casts it.
For example:
df.select{ first().asColumnGroup().firstCol() }
Receiver
The column reference to cast to a SingleColumn<DataRow<C>>.
Return
A SingleColumn<DataRow<C>>.
Type Parameters
C
The type of the (group) column.