*            to force output of model id and source.
     * @return The formatted problem location or an empty string if unknown, never {@code null}.
     */
    public static String formatLocation(ModelProblem problem, String projectId) {
        StringBuilder buffer = new StringBuilder(256);

        if (!problem.getModelId().equals(projectId)) {
            buffer.append(problem.getModelId());

        StringBuilder buffer = new StringBuilder(128);

        buffer.append('[').append(getSeverity()).append("] ");
        buffer.append(getMessage());
        String location = ModelProblemUtils.formatLocation(this, null);
        if (!location.isEmpty()) {
            buffer.append(" @ ");
            buffer.append(location);
        }

        return buffer.toString();
    }

        if (ModelProblem.Severity.ERROR.compareTo(problem.getSeverity()) >= 0) {
            String message = problem.getMessage();

            String location = ModelProblemUtils.formatLocation(problem, projectId);

            if (!location.isEmpty()) {
                message += " @ " + location;
            }

            return handle(message, problem.getException());
        } else {

                        for (ModelProblem problem : problems) {
                            logger.warn(
                                    "{} @ {}", problem.getMessage(), ModelProblemUtils.formatLocation(problem, null));
                        }
                    }
                }
                model = modelResult.getEffectiveModel();
            } catch (ModelBuilderException e) {