e() {         DirectedMultigraph<String> g = new DirectedMultigraph<String>();         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));          Set<Integer> verts = new HashSet<Integer>();         Collections.addAll(verts, 0, 0, 0);         DirectedMultigraph<String> copy = g.copy(verts);         assertEquals(0, copy.order());         assertEquals(0, copy.size());     }       @Test public void test