title: Navigation between NSVIewController
body: <p>I am very new to MAC OSX app development.
  In my application I have three NSViewControllers, which are PracticeController, NoteController and QuestionController. I have to navigate to NoteViewController from PracticeController and QuestionController and comeback to the viewController from which NoteController has navigated.</p>
  
  <p>For example: when we navigate to NoteController from PracticeController, then when we tap on back button from NoteController I have to come to PracticeController, and when we navigate to NoteController from QuestionController, then when we tap on back button from NoteController I have to come to QuestionController.</p>
  
  <p>Please help me how to do this? I am badly searching for it. Thanks.</p>