code: private AttributeValue getSimpleAttributeValue(final Method getter, final Object getterReturnResult) {
          if ( getterReturnResult == null )
              return null;
  
          ArgumentMarshaller marshaller = reflector.getArgumentMarshaller(getter);
          return marshaller.marshall(getterReturnResult);
      }
docs: Returns an {@link AttributeValue} corresponding to the getter and return
  result given, treating it as a non-versioned attribute.