pass-an_optional_classification_value_passes_if_null

[rubendel]

I think this test case is meant to be checking whether an attached classification without an actual value passes an optional classification requirement. However the checked object (IfcWall) does not have a linked classification at all (and should fail I think). Could it be that it is actually the IfcProject entity that should be checked instead of the IfcWall entity?