Graph extends SparseMultigraph<V, E> implements Iterable<V> { public boolean removeVertices(Collection<V> vertices) { boolean b = false; for (V vertex : vertices) { b |= removeVertex(vertex); } return b; }  @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 removeVertex() { Graph<Task, Dependency> app = new Graph<Task, Dependency>(); Task task = new Task("x"); app.addVertex(task); Assert.assertTrue(app.removeVertices(Collections.singleton(task))); Assert.assertEquals(0, app.getVertexCount()); }