This change is necessary but not sufficient to fix the failing tests with  python import errors. Tim, could you please investigate why your change broke these?
This change is necessary but not sufficient to fix the failing tests with 
python import errors. Tim, could you please investigate why your change
broke these?

FluidityProject/multifluids,FluidityProject/multifluids,FluidityProject/multifluids,FluidityProject/multifluids