final String iconNameIfAny) {
final Class<?> correspondingClassIfAny = specification != null? specification.getCorrespondingClass(): null;
final ImageResourceCacheKey key = new ImageResourceCacheKey(correspondingClassIfAny, iconNameIfAny);
ResourceReference resourceReference = resourceReferenceByKey.get(key);
if(resourceReference == null) {
resourceReference = findResourceReferenceFor(key);
resourceReferenceByKey.put(key, resourceReference);
}