final public static String toString(final byte[] key,final int off,final int len){
  if (key == null)   return NULL;
  final StringBuilder sb=new StringBuilder(len * 4 + 2);
  sb.append("[");
  for (int i=off; i < off + len; i++) {
    if (i > 0)     sb.append(",");
    sb.append(Integer.toString(key[i] & 0xff));
  }
  sb.append("]");
  return sb.toString();
}

final public static String toString ( final byte [ ] key , final int off , final int len ) { if ( key == null ) return NULL ; final StringBuilder sb = new StringBuilder ( len * 4 + 2 ) ; sb . append ( "[" ) ; for ( int i = off ; i < off + len ; i ++ ) { if ( i > 0 ) sb . append ( "," ) ; sb . append ( Integer . toString ( key [ i ] & 0xff ) ) ; } sb . append ( "]" ) ; return sb . toString ( ) ; }
formats a key as a series of comma delimited unsigned bytes .
