Non-empty selection of empty dataset.

[1uc]

I'm looking at:

libsonata/src/population.hpp

Line 95 in f65a0ae

if (selection.ranges().empty() || dset.getElementCount() == 0) {

The question is should a non-empty selection of an empty dataset return an empty vector, or should it throw, since we've not returned the requested element? One possible answer is that it's fine since they're all out-of-range and we ignore anything out of range in edge_index too. However, I think that prior to 70559bc out-of-bounds selections would have been an exception for this particular routine.