Where did the files inside test/n3/ come from?

[aucampia]

I'm trying to figure out if the tests inside test/n3 is from some official source or if it is just arbitrary tests, in part because I want to add new things there and also add .{nt,nq} (or even hextuples) files to assert that the graphs contain all expected triples.

If anyone has some insight into this please let me know. As far as I can tell @gromgull did the initial import.