if (realBufferSize.signum () == 0) return realBufferSize;
        public BigInteger getBufferSizeBetween (Object streamSrc, Object streamDst)        {            BigInteger realBufferSize = super.getBufferSizeBetween (streamSrc, streamDst);            int shiftAmount = realBufferSize.subtract (BigInteger.valueOf (1)).bitLength ();            return BigInteger.ONE.shiftLeft (shiftAmount);        }