[DGD] Code libraries for DGD and Hydra

[nikoroleva]

I wrote a bunch of throw away code in the last couple of months and now
starting to feel comfortable using cloudlib as it is. But I reached a point
I can keep doing that for the rest of time, or select a use case which
aligns with this thread.

I think a graph fits that, but I possess only a passing familiarity with
the theory (and, more importantly, meager programming abilities). Won't
know until I try, but I am open to ideas for a learning/demo project.