code: private synchronized void onFailedToLoad(AdView adView, int errorCode) {
          Log.i(TAG, "onAdFailedToLoad " + errorCode);
          mFetchFailCount++;
          mNoOfFetchedAds = Math.max(mNoOfFetchedAds - 1, 0);
          //Since Fetch Ad is only called once without retries
          //hide ad row / rollback its count if still not added to list
          mPrefetchedAds.remove(adView);
          onAdFailed(mNoOfFetchedAds - 1, errorCode, adView);
      }
docs: A handler for failed banner ads
  @param adView