GcFinalization.awaitClear(ref);
  }

  public void testDefaultBehaviorOfPeekForEmptyIteration() {

    AbstractIterator<Integer> empty =
        new AbstractIterator<Integer>() {
          private boolean alreadyCalledEndOfData;

          @Override
          public @Nullable Integer computeNext() {
            if (alreadyCalledEndOfData) {
              fail("Should not have been invoked again");
            }

    GcFinalization.awaitClear(ref);
  }

  public void testDefaultBehaviorOfPeekForEmptyIteration() {

    AbstractIterator<Integer> empty =
        new AbstractIterator<Integer>() {
          private boolean alreadyCalledEndOfData;

          @Override
          public @Nullable Integer computeNext() {
            if (alreadyCalledEndOfData) {
              fail("Should not have been invoked again");
            }