title: Flutter Provider Package doesn't update
body: <p>Aim: I am trying to build the Pomodoro application and after the timer completed I want to update the time spent on the task total time spend. Even though I am using the flutter Provider package, It doesn't work.</p>
  <p>[Task Data][1],[Button in statefulwidget][2],[MainDart File][3],[app task list interface, 0 Min needs to update][4],[Stateful widget interface with button needs to update task data][5]
  [1]: https://i.stack.imgur.com/oUh6j.png
  [2]: https://i.stack.imgur.com/kSpxW.png
  [3]: https://i.stack.imgur.com/6wWLL.png
  [4]: https://i.stack.imgur.com/3tkkH.png
  [5]: https://i.stack.imgur.com/a1xIl.png</p>