ruby-multi-json 1.12.1-1 (amd64 binary) in ubuntu cosmic

 A Ruby library to provide easy switching between different JSON backends,
 including Oj, Yajl, the JSON gem (with C-extensions), the pure-Ruby JSON gem,
 and OkJson.
 The Debian package dependencies only provide Oj by default. If you need
 another backing library, you must install it yourself.