map -package:charset -package:basement -package:foldl -package:invertible -package:bytestring -is:exact is:exact -package:aeson -package:os-string -package:filepath package:case-insensitive

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