code: @Override
    public List<String> getSupportedAuthnContextClassRefs(ProfileRequestContext<?, ?> context) {
      AuthenticationContext authenticationContext = authenticationContextLookupStrategy.apply(context);
      if (authenticationContext == null) {
        log.error("No AuthenticationContext available");
        return Collections.emptyList();
      }
      AuthenticationFlowDescriptor authenticationFlowDescriptor = authenticationContext.getAvailableFlows().get(this.flowName);
      if (authenticationFlowDescriptor == null) {
        log.error("No authentication flow descriptor exists for {}", this.flowName);
        return Collections.emptyList();
      }
      List<String> uris = authenticationFlowDescriptor.getSupportedPrincipals()
        .stream()
        .filter(AuthnContextClassRefPrincipal.class::isInstance)
        .sorted(principalComparator.reversed())
        .map(Principal::getName)
        .collect(Collectors.toList());
  
      log.debug("Supported AuthnContextClassRef URI:s by flow '{}': {}", this.flowName, uris);
      return uris;    
    }
docs: {@inheritDoc}