return this;
int delta = (nInts - start);  for (int i = magLen - 1; i >= nInts; i--) { mag[i] = mag[i - delta]; } for (int i = nInts - 1; i >= start; i--) { mag[i] = 0; }
    public BigInteger shiftRight(int n)    {        if (n == 0)        {            return this;        }        if (n < 0)        {            return shiftLeft( -n);        }        if (n >= bitLength())        {            return (this.sign < 0 ? valueOf( -1) : BigInteger.ZERO);        }        int[] res = new int[this.magnitude.length];        System.arraycopy(this.magnitude, 0, res, 0, res.length);        return new BigInteger(this.sign, shiftRight(0, res, n));    }