rgrig/barista — comment on commit 95f1e2d32579f9f0dad6a5f0228784f3de4b15b5
File: src/classfile/highClass.ml line 1159
By rgrig:

This should be a set, otherwise our termination argument doesn't work, and we'll see parallel arrows.
(Of course, you can represent the set using a list, but you must be careful when you operate on it. Better to change the type.)