Sub::Exporter is an incredibly powerful module, but with that power comes
 great responsibility, as well as some runtime penalties.
 Sub::Exporter::Progressive is a Sub::Exporter wrapper that will let your
 users just use Exporter if all they are doing is picking exports, but use
 Sub::Exporter if your users try to use Sub::Exporter's more advanced
 features, like renaming exports.
 .
 Note that this module will export @EXPORT and @EXPORT_OK package variables
 for Exporter to work. Additionally, if your package uses advanced
 Sub::Exporter features like currying, this module will only use
 Sub::Exporter, so you might as well use it directly.