private boolean setIsOK(byte[] set)
  {
//    byte starting[] = new byte[row.length];
//    System.out.println("Looking at set " + java.util.Arrays.toString(set));
    for (int i=0; i < set.length - 1; i++)
    {
      for (int j=i + 1; j < set.length; j++)
      {
//        System.out.println("Comparing set[" + i + "](" + set[i] + ") and set[" + j + "](" + set[j] + ")");
        if (set[i] == set[j] && set[i] != NULL_VAL && set[j] != NULL_VAL)
        {
//          System.out.println("Set is not OK.");
          return false;
        }
      }
    }
//    System.out.println("Set is OK");
    return true;
  }