title: Android Fragment handle back button press
body: <p>I have some fragments in my activity</p>
  
  <pre><code>[1], [2], [3], [4], [5], [6]
  </code></pre>
  
  <p>And on Back Button Press I must to return from [2] to [1] if current active fragment is [2], or do nothing otherwise.</p>
  
  <p>What is the best practise to do that?</p>
  
  <p><strong>EDIT</strong>: Application must not return to [2] from [3]...[6]</p>