title: Compare activity from getCallingActivity to another
body: <p>I would like to compare the calling activity to others to know which one called the current activity. I tried:</p>
  
  <pre><code>getCallingActivity().getClassName().toString().equals(MainActivity.class.toString())
  </code></pre>
  
  <p>It doesn't work, except by passing a value in the calling Intent, how can we compare classes using <code>getCallingActivity()</code> or <code>getCallingPackage()</code>?</p>