Provide more contextual information in the IFC SPF file header

src/examples/IfcOpenHouse.cpp

@@ -48,6 +48,7 @@ int main(int argc, char** argv) {
 	// The IfcHierarchyHelper is a subclass of the regular IfcFile that provides several
 	// convenience functions for working with geometry in IFC files.
 	IfcHierarchyHelper file;
+	file.filename("IfcOpenHouse.ifc");
 
 	// Start by adding a wall to the file, initially leaving most attributes blank.
 	Ifc2x3::IfcWallStandardCase* south_wall = new Ifc2x3::IfcWallStandardCase(