Graph extends SparseMultigraph<V, E> implements Iterable<V> { public V getVertex(V v) { return getVertex(v.getId()); }  @Override Iterator<V> iterator(); V getVertex(V v); E getEdge(E e); V getVertex(String id); E getEdge(String id); boolean removeVertices(Collection<V> vertices);  }
@Test public void getVertex() { Graph<Task, Dependency> app = new Graph<Task, Dependency>(); Task task = new Task("x"); app.addVertex(task); Assert.assertEquals(task, app.getVertex(task)); }
@Test public void getVertexPerId() { Graph<Task, Dependency> app = new Graph<Task, Dependency>(); Task task = new Task("x"); app.addVertex(task); Assert.assertEquals(task, app.getVertex("x")); }
@Test public void getVertexUnkownId() { Graph<Task, Dependency> app = new Graph<Task, Dependency>(); Assert.assertNull(app.getVertex("y")); }