/**
     * 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

                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());

        //
        // We should get a whole slew of dependencies resolving this artifact transitively
        //
        Dependency d = new Dependency();
        d.setGroupId("org.apache.maven.its");
        d.setArtifactId("b");
        d.setVersion("0.1");
        d.setScope(Artifact.SCOPE_COMPILE);
        Artifact artifact = repositorySystem.createDependencyArtifact(d);

                coreExtension.setGroupId(interpolatedTrimmed(parser.nextText(), "groupId"));
            } else if (checkFieldWithDuplicate(parser, "artifactId", null, parsed)) {
                coreExtension.setArtifactId(interpolatedTrimmed(parser.nextText(), "artifactId"));
            } else if (checkFieldWithDuplicate(parser, "version", null, parsed)) {
                coreExtension.setVersion(interpolatedTrimmed(parser.nextText(), "version"));