code: public static byte[] add(byte[]... b) {
  		int nLen = 0;
  		for (int i = 0; i < b.length; i ++) {
  			nLen += b[i].length;
  		}
  		byte[] lp = new byte[nLen];
  		nLen = 0;
  		for (int i = 0; i < b.length; i ++) {
  			byte[] lpi = b[i];
  			System.arraycopy(lpi, 0, lp, nLen, lpi.length);
  			nLen += lpi.length;
  		}
  		return lp;
  	}
docs: Concatenate <i>n</i> byte arrays