}
    }
    // Trickled element was after index to begin with, no adjustment needed.
    return changes;
  }

  @VisibleForTesting
  void removeAtForTesting(int index) {
    removeAt(index);
  }

  private @Nullable MoveDesc<E> fillHole(int index, E toTrickle) {
    Heap heap = heapForIndex(index);

      }
    }
    // Trickled element was after index to begin with, no adjustment needed.
    return changes;
  }

  @VisibleForTesting
  void removeAtForTesting(int index) {
    removeAt(index);
  }

  private @Nullable MoveDesc<E> fillHole(int index, E toTrickle) {
    Heap heap = heapForIndex(index);

    for (int i = 0; i < heapSize; i++) {
      mmHeap.add(random.nextInt());
    }
    for (int i = 0; i < numberOfModifications; i++) {
      mmHeap.removeAtForTesting(random.nextInt(mmHeap.size()));
      assertIntactUsingSeed(seed, mmHeap);
      mmHeap.add(random.nextInt());
      assertIntactUsingSeed(seed, mmHeap);
    }
  }

    for (int i = 0; i < heapSize; i++) {
      mmHeap.add(random.nextInt());
    }
    for (int i = 0; i < numberOfModifications; i++) {
      mmHeap.removeAtForTesting(random.nextInt(mmHeap.size()));
      assertIntactUsingSeed(seed, mmHeap);
      mmHeap.add(random.nextInt());
      assertIntactUsingSeed(seed, mmHeap);
    }
  }