If you create two VPIntegers of 257 bits (one more than 256) and multiply them the heap will
become corrupted.

class x {
    public static void main(String Args[]) {
        VPInteger a = VPInteger.random(257);
        VPInteger b = VPInteger.random(257);

        System.out.println("This will fail.");
         a = a.mul(b);
        System.out.println("The heap is now corrupted.");
    }
}