*/
    Exception getException();

    /**
     * Gets the message that describes this problem.
     *
     * @return The message describing this problem, never {@code null}.
     */
    String getMessage();

    /**
     * Gets the severity level of this problem.
     *
     * @return The severity level of this problem, never {@code null}.
     */

     * @param line The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param column The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param cause The cause of the problem, may be {@code null}.
     */
    void add(SettingsProblem.Severity severity, String message, int line, int column, Exception cause);

 */
package org.apache.maven.model.building;

import org.apache.maven.model.Model;

/**
 * Describes a problem that was encountered during model building. A problem can either be an exception that was thrown
 * or a simple string message. In addition, a problem carries a hint about its source, e.g. the POM file that exhibits
 * the problem.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */

        validateStringNotEmpty("modelVersion", problems, Severity.ERROR, Version.BASE, m.getModelVersion(), m);

        validateId("groupId", problems, m.getGroupId(), m);

        validateId("artifactId", problems, m.getArtifactId(), m);

        validateStringNotEmpty("packaging", problems, Severity.ERROR, Version.BASE, m.getPackaging(), m);

        collector.add(Problem.Severity.ERROR, "Error message", 10, 5, null);
        collector.add(Problem.Severity.WARNING, "Warning message", 15, 3, null);

        List<Problem> problems = collector.getProblems();
        assertEquals(2, problems.size(), "Should collect both problems");
        assertEquals(Problem.Severity.ERROR, problems.get(0).getSeverity(), "First problem should be ERROR");

            return "Some problems were encountered while processing the POMs";
        }

        long totalProblems = 0;
        long errorProblems = 0;

        for (ProjectBuildingResult result : results) {
            List<ModelProblem> problems = result.getProblems();
            totalProblems += problems.size();

            for (ModelProblem problem : problems) {

     * @param problems the collection of problems to include in the message
     * @return a formatted message including details of all problems
     */
    protected static String buildMessage(String message, ProblemCollector<BuilderProblem> problems) {
        StringBuilder msg = new StringBuilder(message);
        problems.problems().forEach(problem -> msg.append("\n * ")
                .append(problem.getSeverity().name())

        // inheritance assembly
        assembleInheritance(lineage, request, problems);

        Model resultModel = resultData.getModel();

        problems.setSource(resultModel);
        problems.setRootModel(resultModel);

        // model interpolation
        resultModel = interpolateModel(resultModel, request, problems);
        resultData.setModel(resultModel);

     * @param problems The problems that were encountered, may be {@code null}.
     */
    DefaultProjectBuildingResult(String projectId, File pomFile, List<ModelProblem> problems) {
        this.projectId = (projectId != null) ? projectId : "";
        this.pomFile = pomFile;
        this.project = null;
        this.problems = problems != null ? problems : Collections.emptyList();

        assertEquals("0 problems were encountered while building the effective toolchains" + LS, e.getMessage());
    }

    @Test
    void testOneProblem() {
        ProblemCollector problemCollector = ProblemCollectorFactory.newInstance(null);
        problemCollector.add(Problem.Severity.ERROR, "MESSAGE", 3, 5, new Exception());