mutable property

Implementation

ListMutable get mutable {
  // Upon setState ocurrencies, multiple instances of the same list may exist.
  // We're keeping a static reference to the List's state so the transition between
  // instances can be smoother.
  if (!_listState.containsKey(id)) {
    _listState[id] = ListMutable();
  }
  _listState[id]!.timer?.cancel();
  return _listState[id]!;
}