public static byte[] asByteArray(final List<Byte> l){
  final byte[] a=new byte[l.size()];
  for (int i=0; i < a.length; i++) {
    a[i]=l.get(i);
  }
  return a;
}

public static byte [ ] asByteArray ( final List < Byte > l ) { final byte [ ] a = new byte [ l . size ( ) ] ; for ( int i = 0 ; i < a . length ; i ++ ) { a [ i ] = l . get ( i ) ; } return a ; }
return list of boxed bytes as a primitive array .
