update method

Implementation

@override
S update(Updater<S> updater) => delegate.update((state) {
      // Only remember the current state if it is not filtered.
      if (filter == null || !filter!(state)) {
        _past.addLast(state);
        // Limit the number of history items to remember.
        if (limit != null) {
          while (limit! < _past.length) {
            _past.removeFirst();
          }
        }
      }
      // Erase all future states.
      _future.clear();
      return updater(state);
    });