return null == topologicallySortedProjects
                ? Collections.emptyList()
                : Collections.unmodifiableList(topologicallySortedProjects);
    }

    public DependencyResolutionResult getDependencyResolutionResult() {
        return dependencyResolutionResult;
    }

    public MavenExecutionResult setDependencyResolutionResult(DependencyResolutionResult dependencyResolutionResult) {

     */
    List<MavenProject> getTopologicallySortedProjects();

    MavenExecutionResult setDependencyResolutionResult(DependencyResolutionResult result);

    DependencyResolutionResult getDependencyResolutionResult();

    // for each exception
    // - knowing what artifacts are missing
    // - project building exception
    // - invalid project model exception: list of markers
    // - xmlpull parser exception

                @Nonnull
                @Override
                public Optional<DependencyCollectorResult> getDependencyResolverResult() {
                    return Optional.ofNullable(res.getDependencyResolutionResult())
                            .map(r -> new DependencyCollectorResult() {
                                @Override
                                public List<Exception> getExceptions() {

     *
     * @return The result of the dependency resolution for the project or {@code null} if the project dependencies were
     *         not requested.
     */
    DependencyResolutionResult getDependencyResolutionResult();

    }

    public MavenProject getProject() {
        return project;
    }

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

    public DependencyResolutionResult getDependencyResolutionResult() {
        return dependencyResolutionResult;
    }

        assertNotNull(result.getProject());
        assertEquals(1, result.getProblems().size());
        assertEquals(1, result.getProject().getArtifacts().size());
        assertNotNull(result.getDependencyResolutionResult());
    }

    /**
     * Tests whether local version range parent references are build correctly.
     *
     * @throws Exception in case of issue
     */
    @Test