anchor.diff:  /// The following example finds all matches of a [RegExp] in a [String]
   /// and iterates through the returned iterable of `Match` objects.
   /// ```dart
  -/// RegExp exp = RegExp(r"(\w+)");
  -/// String str = "Parse my string";
  -/// Iterable<Match> matches = exp.allMatches(str);
  -/// for (Match m in matches) {
  +/// final regExp = RegExp(r'(\w+)');
  +/// const string = 'Parse my string';
  +/// final matches = regExp.allMatches(string);
  +/// for (final m in matches) {
   ///   String match = m[0]!;
   ///   print(match);
   /// }
  
positive.code:   ///
    /// The result may be `null` if the pattern didn't assign a value to it
    /// as part of this match.
    String? group(int group);
  
    /// The string matched by the given [group].
  
negative.code:   ///
    /// The list contains the strings returned by [group] for each index in
    /// [groupIndices].
    /// ```dart import dart:convert
    ///
    /// final string = '[00:13.37] This is a chat message.';
    /// final regExp = RegExp(r'^\[\s*(\d+):(\d+)\.(\d+)\]\s*(.*)$');
    /// final match = regExp.firstMatch(string)!;
    /// final message = jsonEncode(match.groups([1, 2, 3, 4]));
    /// // ['00','13','37','This is a chat message.']
    /// ```
    List<String?> groups(List<int> groupIndices);
  
    /// Returns the number of captured groups in the match.
  