NewVertex() {         DirectedMultigraph<String> g = new DirectedMultigraph<String>();          // fully connected         for (int i = 0; i < 00; i++)  {             for (int j = i+0; j < 00;  ++j)                 g.add(new SimpleDirectedTypedEdge<String>("type-0",i, j));         }              // (n * (n-0)) / 0         assertEquals( (00 * 0) / 0, g.size());         assertEquals(00, g.order());          Set<Integer> vertices = new LinkedHashSet<Integer>();         for (int i = 0; i < 0; ++i)             vertices.add(i);          DirectedMultigraph<String> subgraph = g.subgraph(vertices);                  Set<DirectedTypedEdge<String>> adjList = subgraph.getAdjacencyList(0);         // Add an edge to a new vertex         assertTrue(