<https://nakanotamachi.net/archives/1124/f0dd24a9-0249-4a1e-b32e-4e1771e80de3>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://nakanotamachi.net/archives/1124/f0dd24a9-0249-4a1e-b32e-4e1771e80de3>