[LuckyTran]

It's a feature not used by everybody, it was implemented I think in the OF 2.something era. All solvers should have these as options because you never know when someone might one day want to add constraints to their problem. It is very easy to apply addition constraints using an fvOptions dict if these lines are coded. It is impossible if not. Another use of fvOptions is to specify sources/sinks usnig only an fvOptions dict and you do not need to recompile the solver. Pretty flexible...


If you want to learn more about what it can do, just google fvOptions. If not, you can ignore it.