}

    @Test
    void testResolveParentThrowsUnresolvableModelExceptionWhenNotFound() throws Exception {
        final Parent parent = new Parent();
        parent.setGroupId("org.apache");
        parent.setArtifactId("apache");
        parent.setVersion("0");

        UnresolvableModelException e = assertThrows(
                UnresolvableModelException.class,
                () -> newModelResolver().resolveModel(parent),

                null,
                new DefaultArtifactHandler("ignore"));
        PluginDescriptor descriptor = new PluginDescriptor();
        descriptor.setGroupId("org.apache.maven.its.plugins");
        descriptor.setArtifactId("maven-it-plugin");
        descriptor.setVersion("0.1");
        List<String> errors = new ArrayList<>();
        mavenPluginValidator.validate(plugin, descriptor, errors);
        assertTrue(

        Exclusion exclusion2 = new Exclusion();
        exclusion2.setGroupId("org.apache.maven");
        exclusion2.setArtifactId("maven-core");

        ExclusionArtifactFilter filter = new ExclusionArtifactFilter(Arrays.asList(exclusion1, exclusion2));

        assertFalse(filter.include(artifact), "Artifact should be excluded by multiple exclusions");
    }

    @Test

    /**
     * Set the artifact ID of the extension.
     *
     * @param artifactId a artifactId object.
     */
    public void setArtifactId(String artifactId) {
        this.artifactId = artifactId;
    } // -- void setArtifactId( String )

    /**
     * Set the class loading strategy: 'self-first' (the default),
     * 'parent-first' (loads classes from the parent, then from the

        model.setGroupId("test.group");
        model.setArtifactId("test-artifact");
        model.setVersion("1.0.0");

        Build build = new Build();
        model.setBuild(build);

        // Add a test plugin
        Plugin originalPlugin = new Plugin();
        originalPlugin.setGroupId("org.apache.maven.plugins");
        originalPlugin.setArtifactId("maven-compiler-plugin");
        originalPlugin.setVersion("3.8.1");

        plugin.setGroupId(groupId);
        plugin.setArtifactId(artifactId);
        plugin.setVersion(version);
        return plugin;
    }

    private Extension createExtension(String groupId, String artifactId, String version) {
        Extension extension = new Extension();
        extension.setGroupId(groupId);
        extension.setArtifactId(artifactId);
        extension.setVersion(version);

                cause);
        // Convert to old type
        CoreExtension oldExtension = new CoreExtension();
        oldExtension.setGroupId(extension.getGroupId());
        oldExtension.setArtifactId(extension.getArtifactId());
        oldExtension.setVersion(extension.getVersion());
        if (extension.getClassLoadingStrategy() != null) {
            oldExtension.setClassLoadingStrategy(extension.getClassLoadingStrategy());

        Parent parent = new Parent();

        parent.setGroupId("test-group");
        parent.setVersion("1000");
        parent.setArtifactId("test-artifact");

        Model model = new Model();

        model.setParent(parent);
        model.setArtifactId("real-artifact");

        MavenProject project = new MavenProject(model);

        project.setGroupId("test");
        project.setArtifactId(artifactId);
        return project;
    }

    private Dependency toDependency(MavenProject mavenProject) {
        Dependency dependency = new Dependency();
        dependency.setGroupId(mavenProject.getGroupId());
        dependency.setArtifactId(mavenProject.getArtifactId());
        dependency.setVersion(mavenProject.getVersion());

        result.setGroupId("org.apache");
        result.setArtifactId("A");
        result.setVersion("1.2");
        return result;
    }

    static Dependency toDependency(MavenProject mavenProject) {
        final Dependency dependency = new Dependency();
        dependency.setArtifactId(mavenProject.getArtifactId());
        dependency.setGroupId(mavenProject.getGroupId());