<https://stormtec.net/blogs/videos/damming-a-river-in-ten-minutes-with-stormbags>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://stormtec.net/blogs/videos/damming-a-river-in-ten-minutes-with-stormbags?comment=92293759108>