@Override
    public Collection<RegisteredService> load() {
        return serviceRegistries.stream()
            .map(ServiceRegistry::load)
            .filter(Objects::nonNull)
            .flatMap(Collection::stream)
            .collect(Collectors.toList());
    }
This is {@link DefaultChainingServiceRegistry}.

@author Misagh Moayyed
@since 5.3.0
core/cas-server-core-services-registry/src/main/java/org/apereo/cas/services/DefaultChainingServiceRegistry.java