*
     * @return The problems that caused this exception, never {@code null}.
     */
    public List<ModelProblem> getProblems() {
        if (result == null) {
            return Collections.emptyList();
        }
        return Collections.unmodifiableList(result.getProblems());
    }

    private static String toMessage(ModelBuildingResult result) {

        assertNotNull(actual);

        boolean hasLocation = actual.getProblems().stream()
                .anyMatch(p -> p.getLineNumber() == lineNumber && p.getColumnNumber() == columnNumber);

        if (!hasLocation) {
            String actualLocations = actual.getProblems().stream()
                    .map(p -> formatLocation(p.getColumnNumber(), p.getLineNumber()))

        ProblemCollector collector2 = ProblemCollectorFactory.newInstance(Collections.singletonList(problem));

        assertNotSame(collector1, collector2);
        assertEquals(0, collector1.getProblems().size());
        assertEquals(1, collector2.getProblems().size());
    }

    @Test
    void testAddProblem() {
        ProblemCollector collector = ProblemCollectorFactory.newInstance(null);
        collector.setSource("pom.xml");

        }

        long totalProblems = 0;
        long errorProblems = 0;

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

            for (ModelProblem problem : problems) {
                if (problem.getSeverity() != ModelProblem.Severity.WARNING) {
                    errorProblems++;

                getProblems(problem.getSeverity()).add(problem);
                return true;
            }
            return false;
        }

        @Override
        public Stream<P> problems(BuilderProblem.Severity severity) {
            requireNonNull(severity, "severity");
            return getProblems(severity).stream();
        }

        assertNotNull(actual);

        boolean hasMessage =
                actual.getProblems().stream().anyMatch(p -> p.getMessage().contains(problemMessage));

        if (!hasMessage) {
            String actualMessages = actual.getProblems().stream()
                    .map(ModelProblem::getMessage)
                    .map(m -> "\"" + m + "\"")

                }

                @Nonnull
                @Override
                public Collection<BuilderProblem> getProblems() {
                    return new MappedCollection<>(res.getProblems(), this::toProblem);
                }

                private BuilderProblem toProblem(ModelProblem problem) {
                    return new BuilderProblem() {

     *
     * @return The problems that were encountered during the project building, can be empty but never {@code null}.
     */
    List<ModelProblem> getProblems();

    /**
     * Gets the result of the dependency resolution for the project.
     *
     * @return The result of the dependency resolution for the project or {@code null} if the project dependencies were

    public File getPomFile() {
        return pomFile;
    }

    @Override
    public MavenProject getProject() {
        return project;
    }

    @Override
    public List<ModelProblem> getProblems() {
        return problems;
    }

    @Override
    public DependencyResolutionResult getDependencyResolutionResult() {
        return dependencyResolutionResult;
    }

        long totalProblemsCount = 0;

        for (ProjectBuildingResult result : results) {
            projects.add(result.getProject());

            int problemsCount = result.getProblems().size();
            totalProblemsCount += problemsCount;
            if (problemsCount != 0 && LOGGER.isWarnEnabled()) {
                LOGGER.warn("");
                LOGGER.warn(