modify the transform of sub assembly to its parent level

problem

I'm trying to modify the transform of sub assembly to its parent level using XCAFDoc_Location::Set() method. The problem is when I export the model to step and read it again, I find the location doesn't change. I have tried to solve is, using shape_tool->UpdateAssemblies() or doc->Recompute().

gp_Trsf newTransform;
newTransform.SetTranslation(gp_Vec(100.0, 0.0, 0.0));
TopLoc_Location newLoc = currentLoc * TopLoc_Location(newTransform);

TDF_Label newlabel;
XCAFDoc_Location::Set(foundLabel, newLoc);
shapeTool->UpdateAssemblies();