map -package:containers -package:charset -package:invertible -is:exact -package:conduit -package:basement -package:bytestring -is:exact -package:filepath package:case-insensitive is:exact

map :: FoldCase s2 => (s1 -> s2) -> CI s1 -> CI s2
case-insensitive Data.CaseInsensitive
Transform the original string-like value but keep it case insensitive.