*
     * @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) {

        ToolchainsBuildingResult result = toolchainBuilder.build(request);
        assertNotNull(result.getEffectiveToolchains());
        assertNotNull(result.getProblems());
        assertEquals(0, result.getProblems().size());
    }

    @Test
    void testBuildRequestWithUserToolchains() throws Exception {
        Properties props = new Properties();
        props.put("key", "user_value");

        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");

                }

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

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

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

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

            }
        }

        if (hasErrors(problems.getProblems())) {
            throw new SettingsBuildingException(problems.getProblems());
        }

        return new DefaultSettingsBuildingResult(userSettings, problems.getProblems());
    }

    private boolean hasErrors(List<SettingsProblem> problems) {
        if (problems != null) {

            if (cause instanceof ModelBuildingException modelBuildingException) {
                StringBuilder message = new StringBuilder("In: " + pom + "\n\n");
                for (ModelProblem problem : modelBuildingException.getProblems()) {
                    message.append(problem).append("\n");
                }
                System.out.println(message);
                fail(message.toString());
            }

            throw e;

        context.eventSpyDispatcher.onEvent(toolchainsResult);

        context.effectiveToolchains = toolchainsResult.getEffectiveToolchains();

        if (toolchainsResult.getProblems().hasWarningProblems()) {
            int totalProblems = toolchainsResult.getProblems().totalProblemsReported();
            context.logger.info("");
            context.logger.info(String.format(

        Result<? extends ProjectDependencyGraph> graphResult = buildGraph(session);

        if (graphResult.hasErrors()) {
            return addExceptionToResult(
                    result, graphResult.getProblems().iterator().next().getException());
        }

        try {
            session.setProjectMap(getProjectMap(session.getProjects()));
        } catch (DuplicateProjectException e) {

                    server = result.getServer();

                    if (logger.isDebugEnabled()) {
                        for (SettingsProblem problem : result.getProblems()) {
                            logger.debug(problem.getMessage(), problem.getException());
                        }
                    }