* @param problems The container used to collect problems that were encountered, must not be {@code null}.
     */
    default Model injectProfile(
            Model model, Profile profile, ModelBuilderRequest request, ModelProblemCollector problems) {
        return injectProfiles(model, List.of(profile), request, problems);
    }

    /**

        inputModel = injectProfileActivations(inputModel, interpolatedActivations);

        // profile injection
        inputModel = profileInjector.injectProfiles(inputModel, activePomProfiles, request, problems);
        inputModel = profileInjector.injectProfiles(inputModel, activeExternalProfiles, request, problems);

        return inputModel;
    }

    @SuppressWarnings("checkstyle:methodlength")

    // we want to store the model used as they key.
    private static final Model KEY = Model.newInstance();

    private final ProfileModelMerger merger = new ProfileModelMerger();

    @Override
    public Model injectProfiles(
            Model model, List<Profile> profiles, ModelBuilderRequest request, ModelProblemCollector problems) {
        Model result = CACHE.computeIfAbsent(model, k -> new ConcurrentHashMap<>())