title: Change animation of fragment already in stack
body: <p>Assume I run the following code to place a fragment into the stack. It sets the animations for when I initially view the fragment and for when the fragment is exited. </p>
  
  <pre><code>FragmentManager fragmentManager = getFragmentManager();
  FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
  fragmentTransaction.setCustomAnimations(R.anim.slide_left,
                                          R.anim.no_anim,
                                          R.anim.no_anim_show,
                                          R.anim.slide_right_away);
  fragmentTransaction.replace(R.id.container, fragment, tag);
  fragmentTransaction.addToBackStack(tag);
  fragmentTransaction.commit();
  </code></pre>
  
  <p>If i want to change the exit animation at a later time, how could I do this? As in,  if I had the following code:</p>
  
  <pre><code>getFragmentManager().popBackStack();
  </code></pre>
  
  <p>But I want a different animation then the one I originally placed into the stack.</p>