title: Save state of fragments in backstack
body: <p>My problem is generally described in this question:
  <a href="https://stackoverflow.com/questions/15313598/once-for-all-how-to-correctly-save-instance-state-of-fragments-in-back-stack">Once for all, how to correctly save instance state of Fragments in back stack?</a></p>
  
  <p>But i can't understand how the accepted answer is related to it.</p>
  
  <p>To keep it short:</p>
  
  <ol>
  <li><p>There are 2 fragments A and B.</p></li>
  <li><p>I go from A to B using transaction.replace() and add transaction to backstack.</p></li>
  <li><p>I rotate screen -> fragment A is not visible, but it's onSaveInstanceState is called - everything ok up to this point.</p></li>
  <li><p>I rotate screen again. Again A's onSaveInstanceState is called, but now it's view doesn't exist so I can't save it's state.</p></li>
  </ol>
  
  <p>What's the purpose of using getFragment/putFragment, as accepted answer suggests?
  When my fragment is in the backstack there's no point in keeping reference to it I guess.
  Thanks.</p>