_:n041304dc9d8d400fa9be60bed1f65682xb2
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://blog.shitake4.tech/entry/2018/02/05/Rails%E3%81%AE%E3%82%BD%E3%83%BC%E3%82%B9%E3%82%B3%E3%83%BC%E3%83%89%E8%AA%AD%E3%82%93%E3%81%A7%E3%81%BF%E3%82%8B_%7C_Active_Support_to_json%E7%B7%A8>