title: Can't implement adMob AdListener Class
body: <p>Im getting this error:</p>
  
  <pre><code>- The type AdListener cannot be a superinterface of AdManager; a superinterface must be an 
           interface
  </code></pre>
  
  <p>When im trying to implement ADMOB AdListener on my app:</p>
  
  <pre><code>import com.google.android.gms.ads.AdListener;
  
  public class AdManager implements AdListener{
  </code></pre>
  
  <p>What am i doing wrong?</p>