map -package:containers -package:charset is:exact -package:insert-ordered-containers -package:base-compat -package:bytestring -package:base-prelude -package:basement -package:psqueues -package:pipes 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.