Any particular reason `Iterable<T>.groupByTo...

# stdlib

[spand]

Any particular reason Iterable<T>.groupByTo requires destination to be a list and not a collection ?

[Dominaezzz]

Order preservation I think.
Also, there's no nice way to allow users to choose what type of Collection is used, since generics are erased.
I think you can use groupingBy if you want the flexibility.

[spand]

Ah, silly me. I thought for a second the destination was the List itself but its the map.