<https://www.wgbh.org/news/2014-06-30/why-140-characters-when-one-will-do-tracing-the-emoji-evolution>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.wgbh.org/news/2014-06-30/why-140-characters-when-one-will-do-tracing-the-emoji-evolution>