anchor.diff:      modifyOne(arg.d);
       modifyOne(arg.n);
       modifyOne(arg.b);
  +    modifyOne(arg.s);
       modifyOne(arg.l);
       modifyOne(arg.m);
     }
  
positive.code:     arg.d += 1;
      arg.n += 1;
      arg.b = true;
      arg.l.add(4);
      arg.m['four'] = 4;
    }
  
negative.code: }
  
  void modifyOne(var arg) {
    if(arg is String) arg = "Completely Different";
    if(arg is List) arg[0] = 100;
    if(arg is Map) arg['one'] = 100;
    if(arg is SideEffect) {
  