private MetadataGraph findLinkedSubgraph(MetadataGraph g) {
        if (g.getVertices().size() == 1) {
            return g;
        }

        List<MetadataGraphVertex> visited = new ArrayList<>(g.getVertices().size());
        visit(g.getEntry(), visited, g);

        List<MetadataGraphVertex> dropList = new ArrayList<>(g.getVertices().size());

        // collect drop list

        assertNotNull(res, "null graph after resolver");
        assertNotNull(res.getVertices(), "no vertices in the resulting graph after resolver");

        assertNotNull(res.getExcidentEdges(v1), "no edges in the resulting graph after resolver");

        assertEquals(4, res.getVertices().size(), "wrong # of vertices in the resulting graph after resolver");
        assertEquals(
                2,

        protected ClasspathGraphVisitor(MetadataGraph cleanGraph, ClasspathContainer cpc) {
            this.cpc = cpc;
            this.graph = cleanGraph;

            visited = new ArrayList<>(cleanGraph.getVertices().size());
        }

        // -----------------------------------------------------------------------
        protected void visit(MetadataGraphVertex node) {
            ArtifactMetadata md = node.getMd();

    public MetadataGraphVertex getEntry() {
        return entry;
    }

    public void setEntry(MetadataGraphVertex entry) {
        this.entry = entry;
    }

    public TreeSet<MetadataGraphVertex> getVertices() {
        return vertices;
    }

    public List<MetadataGraphEdge> getIncidentEdges(MetadataGraphVertex vertex) {
        checkEdges();
        return incidentEdges.get(vertex);
    }