private ArtifactType requireType(String id) {
            return requireNonNull(registry.get(id), "Type " + id + " not found but is required");
        }

        @Override
        public boolean visitEnter(DependencyNode node) {
            ArtifactType currentType = jar;
            if (node.getArtifact() != null) {
                if (node.getArtifact().getProperties().containsKey(ArtifactProperties.TYPE)) {