title: Fragments: Replacing a fragment causes it to reinstantiate on back pressed
body: <p>I am using one activity all fragment approach. Now I have a fragment A and when I go to fragment B I replace A in container with B with </p>
  
  <pre><code>.replace(R.id.master_fragment_container_above_toolbar, fragment)
                  .addToBackStack("")
                  .commit();
  </code></pre>
  
  <p>As you can see, I have added fragment to backStack. But now when I press back on device, it re-instantiates the fragment A and thus takes time to go back.</p>
  
  <p>Is there another way to do it? I don't want to use <code>add()</code>, if I add multiple fragments to container, it will take up a lot of memory.</p>