artg4

I looked at this file:
https://cdcvs.fnal.gov/redmine/projects/artg4/repository/revisions/develop/entry/services/Material_service.cc because I wanted to add a new function to return a newXenonGas()

I see two issues.
1) The parameter order temperature and pressure of NewVacuum() seems to be swapped from the one specified in /gm2/app/software/testReleases3/external/geant4/v4_9_5_p01/sour
ce/geant4.9.5.p01/source/materials/include/G4Material.hh

2) The return type of newVacuum() is G4Material* , however, the implementation has no return statement. Why doesn't this cause a compilation error? Is there something tricky that I don't understand?