DClassElement (DClassElement classElement) { final DClassElement existingClassElement = containingClasses.get(classElement.getName()); if (existingClassElement != null) { final Collection<DPropertyElement> properties = existingClassElement.getProperties(); final Set<DMethodElement> methods = existingClassElement.getMethods(); classElement.addProperties(properties); classElement.addMethods(methods); } containingClasses.put(classElement.getName(), classElement); return classElement; }