@Override
  public String toString() {
    StringBuilder builder = new StringBuilder();
    builder.append("RegExpMatch{");
    final int max = groups.size();
    for (int i = 0; i < max; i += 2) {
      builder.append('[').append(groups.getInt(i)).append(", ").append(groups.getInt(i + 1)).append(']');
    }
    builder.append('}');
    return builder.toString();
  }
@Override
  public String toString()