map object

main.dart

class Test {
  Map<String, String> data = {};
    
  Test();
  
  String toString() {
    return '$data';
  }
}

void main() {
  final t1 = Test();
  final t2 = Test();
  
  t1.data = t2.data;
  
  t1.data['Happy'] = 'Yes';
  t2.data['Happy'] = 'No';
  
  print(t1);
  print(t2);
}