groups method Null safety

List<String?> groups(
  1. List<int> groupIndices

A list of the groups with the given indices.

The list contains the strings returned by group for each index in groupIndices.

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);