I use this source code as a torture test example for implementing java-nested package visualisation.
I (the author of GitUML) also recently added optimisations so that nest packages with no classes would collapse into a.b.c etc. syntax rather than showing one nested box inside the other. The optimised look is cleaner.
This feature is now generally built into GitUML Java reverse engineering.
Modules being visualised
List of repository modules/files being visualised in the above diagram: