code: public LinkedHashSet<Class<?>> getRegisteredKryoTypes() {
  		if (isForceKryoEnabled()) {
  			// if we force kryo, we must also return all the types that
  			// were previously only registered as POJO
  			LinkedHashSet<Class<?>> result = new LinkedHashSet<>();
  			result.addAll(registeredKryoTypes);
  			for(Class<?> t : registeredPojoTypes) {
  				if (!result.contains(t)) {
  					result.add(t);
  				}
  			}
  			return result;
  		} else {
  			return registeredKryoTypes;
  		}
  	}
docs: Returns the registered Kryo types.