@PropertyGetter("encounterProviders")
 public static Set<EncounterProvider> getActiveEncounterProviders(Encounter instance) {
   Set<EncounterProvider> encounterProviders = instance.getEncounterProviders();
   Set<EncounterProvider> providers = new LinkedHashSet<EncounterProvider>();
   for (EncounterProvider encounterProvider : encounterProviders) {
     if (!encounterProvider.isVoided()) {
       providers.add(encounterProvider);
     }
   }
   return providers;
 }