code: @Override
    public VType indexReplace(int index, VType newValue) {
      assert index >= 0 : "The index must point at an existing key.";
      assert index <= mask ||
             (index == mask + 1 && hasEmptyKey);
  
      VType previousValue = Intrinsics.<VType> cast(values[index]);
      values[index] = newValue;
      return previousValue;
    }
docs: {@inheritDoc}