private void ensureCapacityHelper(int minCapacity) {
    int oldCapacity = elementData.length;
    if (minCapacity > oldCapacity) {
        Object[] oldData = elementData;
        int newCapacity = (capacityIncrement > 0) ?
        (oldCapacity + capacityIncrement) : (oldCapacity * 2);
            if (newCapacity < minCapacity) {
        newCapacity = minCapacity;
        }
            elementData = Arrays.copyOf(elementData, newCapacity);
    }
    }