public void add (String groupId, String artifactId, String version) {
IClassPackageResolver resolver = ClassPackageContext.getPackageResolver();
if (resolver == null) throw new IllegalStateException("No class package context resolver available, this feature is disabled");
IClassPackageDependencyReference ref = new ClassPackageDependencyReferenceImpl(groupId, artifactId, version, null);
IClassPackage pkg = ClassPackageUtil.get(resolver, ref, true);
if (pkg == null) throw new IllegalArgumentException("Could not resolve: " + ref);
this.getJarFileUrls().add(pkg.getMainJarSource().getURL());
}