return emptySet();
}
private IndexedElement referredField(AbstractCustomOption customOption, OptionField field,
Provider<IndexedElement> provider) {
OptionField previous = null;
boolean isFirstField = true;
for (OptionField current : options.fieldsOf(customOption)) {
if (current == field) {
return (isFirstField) ? provider.get() : optionFields.sourceOf(previous);
}