@Override
    public String toString() {
      StringBuilder s = new StringBuilder();
      for (int i = 0; i < nextOffsets.length; i++) {
        int[] targets = nextOffsets[i];
        if (targets != null && targets.length != 0 && targets[0] != -1) {
          if (s.length() != 0) s.append(' ');
          s.append('(').append(i).append("->");
          for (int j = 0; j < targets.length && targets[j] != -1; j++) {
            if (j != 0) s.append(",");
            s.append(targets[j]);
          }
          s.append(')');
        }
      }
      return s.toString();
    }
@Override
    public String toString()