public E get(int index) {
        if (index >= mSize || index + mSize < 0) {
            throw new IndexOutOfBoundsException("Index: " + index + ", Size: " + mSize);
        }

        return index < 0 ? mElements.get(index + mSize) : mElements.get(index);
    }
@Test
    void testIllegalGet() throws Exception {
        Assertions.assertThrows(IndexOutOfBoundsException.class, () -> {
            Stack<String> stack = new Stack<String>();
            stack.get(1);
        });
    }