parent.setArtifactId("apache");
        parent.setVersion("1");

        assertNotNull(this.newModelResolver().resolveModel(parent.getDelegate(), new AtomicReference<>()));
        assertEquals("1", parent.getVersion());
    }

    @Test
    void testResolveParentSuccessfullyResolvesExistingParentUsingHighestVersion() throws Exception {
        final Parent parent = new Parent();
        parent.setGroupId("org.apache");

            throws ModelBuilderException {
        problems.setSource(childModel);

        Parent parent = childModel.getParent();

        String groupId = parent.getGroupId();
        String artifactId = parent.getArtifactId();
        String version = parent.getVersion();

        ModelResolver modelResolver = getModelResolver(request);
        Objects.requireNonNull(

            if (!parent.getVersion().equals(newVersion)) {
                modified.set(parent.withVersion(newVersion));
            }

            return resolveModel(parent.getGroupId(), parent.getArtifactId(), newVersion);
        } catch (final VersionRangeResolutionException e) {
            throw new UnresolvableModelException(
                    e.getMessage(), parent.getGroupId(), parent.getArtifactId(), parent.getVersion(), e);

        }

        @Override
        public Object[] toArray() {
            return parent.toArray();
        }

        @Override
        public <T> T[] toArray(final T[] a) {
            return parent.toArray(a);
        }

        @Override
        public boolean add(final E e) {
            return parent.add(e);
        }

        @Override

        final Parent parent = Parent.newBuilder()
                .groupId("org.apache")
                .artifactId("apache")
                .version("1")
                .build();

        assertNotNull(this.newModelResolver().resolveModel(session, parent, new AtomicReference<>()));
        assertEquals("1", parent.getVersion());
    }

    @Test

        builder = Model.newBuilder(model);
        modelMerger.mergeModel_ModelVersion(builder, model, parent, false, null);
        assertEquals("5.0.0", builder.build().getModelVersion());
    }

    // ArtifactId is neither inherited nor injected
    @Test
    void testMergeModel_ArtifactId() {
        Model parent = Model.newBuilder().artifactId("PARENT").build();
        Model model = Model.newInstance();

    assertEquals("com", InternetDomainName.from("google.com").parent().toString());
    assertEquals("uk", InternetDomainName.from("co.uk").parent().toString());
    assertEquals("google.com", InternetDomainName.from("www.google.com").parent().toString());

    try {
      InternetDomainName.from("com").parent();
      fail("'com' should throw ISE on .parent() call");
    } catch (IllegalStateException expected) {
    }
  }

    private static final String LANG_KEY = "lang";
    private final Map<String, Object> parent;

    public DocMap(final Map<String, Object> parent) {
        this.parent = parent;
    }

    @Override
    public int size() {
        return parent.size();
    }

    @Override
    public boolean isEmpty() {
        return parent.isEmpty();
    }

    @Override
    public boolean containsKey(final Object key) {

        MavenProject project = getMavenProject(artifactId);
        Parent parent = new Parent();
        parent.setGroupId(parentProject.getGroupId());
        parent.setArtifactId(parentProject.getArtifactId());
        project.getModel().setParent(parent);
        return project;
    }

    private MavenProject getMavenProject(String artifactId) {

    Path file = root().resolve("parent/nonexistent.file");
    Path parent = file.getParent();
    assertFalse(Files.exists(parent));
    assertThrows(IOException.class, () -> MoreFiles.createParentDirectories(file));
  }

  public void testCreateParentDirectories_nonDirectoryParentExists() throws IOException {
    Path parent = createTempFile();
    assertTrue(Files.isRegularFile(parent));
    Path file = parent.resolve("foo");