private static byte[] addHeadByte(byte[] array,byte b){
  byte[] ret=new byte[array.length + 1];
  ret[0]=b;
  System.arraycopy(array,0,ret,1,array.length);
  return ret;
}

private static byte [ ] addHeadByte ( byte [ ] array , byte b ) { byte [ ] ret = new byte [ array . length + 1 ] ; ret [ 0 ] = b ; System . arraycopy ( array , 0 , ret , 1 , array . length ) ; return ret ; }
returns a copy of the specified array with the specified byte added at the front .
