Model model = (Model) list.getParentSBMLObject();
if (elementName.equals("unitDefinition")
&& list.getSBaseListType().equals(
ListOf.Type.listOfUnitDefinitions)) {
UnitDefinition unitDefinition = (UnitDefinition) newContextObject;
model.addUnitDefinition(unitDefinition);
return unitDefinition;
} else if (elementName.equals("compartment")
&& list.getSBaseListType().equals(
ListOf.Type.listOfCompartments)) {