map -package:containers -package:basement -package:conduit -is:exact -package:pipes -package:imports -package:bytestring -is:exact -package:invertible -package:ghc -package:base package:hedgehog is:exact

Generates a map using a Range to determine the length. This may fail to generate anything if the keys produced by the generator do not account for a large enough number of unique items to satify the required map size.