title: Android activity lifecycle callbacks
body: <p>Do activity lifecycle callbacks have to be implemented in pairs?</p>
  
  <p>e.g.</p>
  
  <ul>
  <li>if you override <code>onCreate</code> you must also override <code>onDestroy</code> ?</li>
  <li>if you override <code>onStart</code> you must also override <code>onStop</code> ? </li>
  <li>if you override <code>onResume</code> you must also override <code>onPause</code> ?</li>
  </ul>
  
  <p>i.e. would your app crash if you implement <code>onCreate</code> but omit to implement <code>onDestroy</code> say?</p>
  
  <p>Is it just good practice to implement in pairs, or does it not matter at all (just implement what you need)?</p>