static class ElementSetGenerator<E> implements TestSetGenerator<E> {
    final OneSizeTestContainerGenerator<Collection<E>, E> gen;

    ElementSetGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Set<E> create(Object... elements) {

      while (graph.nodes().size() < NUM_NODES) {
        graph.addNode(gen.nextInt(NODE_POOL_SIZE));
      }
      ArrayList<Integer> nodeList = new ArrayList<>(graph.nodes());
      while (graph.edges().size() < NUM_EDGES) {
        graph.putEdge(getRandomElement(nodeList, gen), getRandomElement(nodeList, gen));
      }
      ArrayList<EndpointPair<Integer>> edgeList = new ArrayList<>(graph.edges());

    final OneSizeTestContainerGenerator<Collection<E>, E> gen;

    private ReserializedListGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public List<E> create(Object... elements) {

      while (graph.nodes().size() < NUM_NODES) {
        graph.addNode(gen.nextInt(NODE_POOL_SIZE));
      }
      ArrayList<Integer> nodeList = new ArrayList<>(graph.nodes());
      while (graph.edges().size() < NUM_EDGES) {
        graph.putEdge(getRandomElement(nodeList, gen), getRandomElement(nodeList, gen));
      }
      ArrayList<EndpointPair<Integer>> edgeList = new ArrayList<>(graph.edges());

    private ReserializedSetGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Set<E> create(Object... elements) {
      return (Set<E>) SerializableTester.reserialize(gen.create(elements));
    }

    final OneSizeTestContainerGenerator<Collection<E>, E> gen;

    private ReserializedListGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public List<E> create(Object... elements) {

      Collections.shuffle(nodeList, gen);
      for (Integer node : nodeList) {
        assertThat(network.addNode(node)).isTrue();
      }
      Collections.shuffle(edgeList, gen);
      for (Object edge : edgeList) {
        assertThat(
                network.addEdge(
                    getRandomElement(nodeList, gen), getRandomElement(nodeList, gen), edge))
            .isTrue();
      }

    private ReserializedCollectionGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Collection<E> create(Object... elements) {
      return SerializableTester.reserialize(gen.create(elements));
    }

    @Override

    private ReserializedSetGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Set<E> create(Object... elements) {
      return (Set<E>) SerializableTester.reserialize(gen.create(elements));
    }

      Collections.shuffle(nodeList, gen);
      for (Integer node : nodeList) {
        assertThat(network.addNode(node)).isTrue();
      }
      Collections.shuffle(edgeList, gen);
      for (Object edge : edgeList) {
        assertThat(
                network.addEdge(
                    getRandomElement(nodeList, gen), getRandomElement(nodeList, gen), edge))
            .isTrue();
      }