ValueSource source;
if (initialValue != null) {
source = new FixedValueSource(container.getValue());
property.setInitialValue(container.getValue());
} else if (propertyReference != null) {
source = new PropertyValueSource(propertyReference);
} else if (computedPropertyRef != null) {
source = new ComputedValueSource(
computedPropertyRef, computedRef.getRules());
} else {
source = new NullValueSource();