Fix representation where removing a representation left objects with an empty mesh. Now a proper empty is used.

src/blenderbim/test/bim/test_feature.py

@@ -356,6 +356,11 @@ def the_object_name_is_not_an_ifc_element(name):
     assert id == 0, f"The ID is {id}"
 
 
+@then(parsers.parse('the object "{name}" has no data'))
+def the_object_name_has_no_data(name):
+    assert the_object_name_exists(name).data is None
+
+
 @then(parsers.parse('the object "{name}" has data which is an IFC representation'))
 def the_object_name_is_not_an_ifc_element(name):
     id = the_object_name_exists(name).data.BIMMeshProperties.ifc_definition_id