Doc <-> Code Unit Test has a bug.

[SJrX]

    Set<String> codeButNotDoc = new TreeSet<>(code);    
    Set<String> docButNotCode = new TreeSet<>(code);
    codeButNotDoc.removeAll(doc);
    docButNotCode.removeAll(code);

Second line should be (doc) not (code).

If you switch it, there are a few errors, but I didn't feel like tracking them down at the moment.

See also #96