* @return The identifier of the POM or an empty string if not known, never {@code null}.
     */
    public String getModelId() {
        if (result == null || result.getModelIds().isEmpty()) {
            return "";
        }
        return result.getModelIds().get(0);
    }

    /**
     * Gets the problems that caused this exception.
     *
     * @return The problems that caused this exception, never {@code null}.

     * an empty string that by definition denotes the super POM.
     *
     * @return The model identifiers from the lineage of models, never {@code null}.
     */
    List<String> getModelIds();

    /**
     * Gets the assembled model.
     *
     * @return The assembled model, never {@code null}.
     */
    Model getEffectiveModel();

    /**

    }

    public DefaultModelBuildingResult setEffectiveModel(Model model) {
        this.effectiveModel = model;

        return this;
    }

    @Override
    public List<String> getModelIds() {
        return modelIds;
    }

    public DefaultModelBuildingResult addModelId(String modelId) {
        // Intentionally notNull because Super POM may not contain a modelId

                req.getException());

        add(problem);
    }

    public ModelBuildingException newModelBuildingException() {
        ModelBuildingResult result = this.result;
        if (result.getModelIds().isEmpty()) {
            DefaultModelBuildingResult tmp = new DefaultModelBuildingResult();
            tmp.setEffectiveModel(result.getEffectiveModel());
            tmp.setProblems(getProblems());