use v6.d.PREVIEW; use Cro::HTTP::BodySerializer; use XML::Writer; class Ultramarine::Serialiser::JSON is Cro::HTTP::BodySerializer::JSON { method serialize(Cro::HTTP::Message $message, $body --> Supply) { nextwith $message, { subsonic-response => { :version<1.13.0>, |$body, }, }; } }