operator [] method

*<Null safety>*

• @override

V? operator [] (Object? key) override

Implementation

@override
V? operator [](Object? key) {
  for (var map in _maps) {
    // Avoid two hash lookups on a positive hit.
    var value = map[key];
    if (value != null || map.containsKey(value)) {
      return value;
    }
  }
  return null;
}