lockGraphNodesPerType = new MapMaker().weakKeys().makeMap();

  /** Creates a {@code CycleDetectingLockFactory.WithExplicitOrdering<E>}. */
  public static <E extends Enum<E>> WithExplicitOrdering<E> newInstanceWithExplicitOrdering(
      Class<E> enumClass, Policy policy) {
    // createNodes maps each enumClass to a Map with the corresponding enum key
    // type.

    CycleDetectingLockFactory.WithExplicitOrdering<MyOrder> factory2 =
        newInstanceWithExplicitOrdering(MyOrder.class, Policies.THROW);
    lock1 = factory2.newReentrantLock(MyOrder.FIRST);
    lock2 = factory2.newReentrantLock(MyOrder.SECOND);
    lock3 = factory2.newReentrantLock(MyOrder.THIRD);

    CycleDetectingLockFactory.WithExplicitOrdering<OtherOrder> factory3 =

    CycleDetectingLockFactory.WithExplicitOrdering<MyOrder> factory2 =
        newInstanceWithExplicitOrdering(MyOrder.class, Policies.THROW);
    lock1 = factory2.newReentrantLock(MyOrder.FIRST);
    lock2 = factory2.newReentrantLock(MyOrder.SECOND);
    lock3 = factory2.newReentrantLock(MyOrder.THIRD);

    CycleDetectingLockFactory.WithExplicitOrdering<OtherOrder> factory3 =