private DefaultBuildPluginManager pluginManager;

    protected String getProjectsDirectory() {
        return "src/test/projects/plugin-manager";
    }

    @Test
    void testPluginLoading() throws Exception {
        MavenSession session = createMavenSession(null);
        Plugin plugin = new Plugin();
        plugin.setGroupId("org.apache.maven.its.plugins");
        plugin.setArtifactId("maven-it-plugin");

    /*
     * (non-Javadoc)
     * @see junit.framework.TestCase#setUp()
     */
    @BeforeEach
    public void setUp() throws Exception {
        properties = new MavenProperties();
        properties.load(new StringReader(TEST_PROPERTIES));
    }

    @Test
    public void testSpaces() throws Exception {
        String config = "\n" + "\n"
                + "    \n"
                + "                \n"

/**
 * The Exception class throw by the {@link ToolchainManager}.
 *
 * @since 4.0.0
 */
@Experimental
public class ToolchainManagerException extends MavenException {

    /**
     * @param message the message to give
     * @param e the {@link Exception}
     */
    public ToolchainManagerException(String message, Exception e) {
        super(message, e);
    }

     */
    @Nonnull
    String getLocation();

    /**
     * Gets the exception that caused this problem (if any).
     *
     * @return the exception that caused this problem or {@code null} if not applicable
     */
    @Nullable
    Exception getException();

    /**
     * Gets the message that describes this problem.
     *

/**
 * The Exception class throw by the {@link ProjectBuilder} service.
 *
 * @since 4.0.0
 */
@Experimental
public class ProjectBuilderException extends MavenException {

    /**
     * @param message the message to give
     * @param e the {@link Exception}
     */
    public ProjectBuilderException(String message, Exception e) {
        super(message, e);
    }

/**
 * The Exception class throw by the {@link Prompter} service.
 *
 * @since 4.0.0
 */
@Experimental
public class PrompterException extends MavenException {

    public PrompterException(String message) {
        super(message);
    }

    /**
     * @param message the message to give
     * @param e the {@link Exception}
     */

    void projectFinished(String projectId);

    void executionFailure(String projectId, boolean halted, String exception);

    void mojoStarted(ExecutionEvent event);

    void finish(int exitCode) throws Exception;

    void fail(Throwable t) throws Exception;

    void log(String msg);

    void transfer(String projectId, TransferEvent e);

    @Nested
    @DisplayName("Artifact Extraction")
    class GAVExtractionTests {

        @Test
        @DisplayName("should extract Artifact from complete POM")
        void shouldExtractGAVFromCompletePOM() throws Exception {
            String pomXml = PomBuilder.create()
                    .groupId("com.example")
                    .artifactId("test-project")
                    .version("1.0.0")
                    .build();

 */
@Deprecated(since = "4.0.0")
public class InvalidRepositoryException extends Exception {

    /**
     * The repository that raised this error, can be {@code null}.
     */
    private Repository repository;

    /**
     * Creates a new exception with specified detail message and cause for the given repository.
     *
     * @param message The detail message, may be {@code null}.

    MetadataGraphVertex v3;
    MetadataGraphVertex v4;

    // ------------------------------------------------------------------------------------------
    @BeforeEach
    void setUp() throws Exception {
        graph = new MetadataGraph(4, 3);
        /*
         *       v2
         *   v1<
         *       v3-v4
         *
         */
        v1 = graph.addVertex(new ArtifactMetadata("g", "a1", "1.0"));