@Override
 protected Void doInBackground(Void... voids) {
   try {
     Facebook.publishInstall(Facebook.this, mApplicationId, mApplicationContext);
   } catch (Exception e) {
     Util.logd("Facebook-publish", e.getMessage());
   }
   return null;
 }
 /**
  * Manually publish install attribution to the facebook graph. Internally handles tracking repeat
  * calls to prevent multiple installs being published to the graph.
  *
  * @param context
  * @return returns false on error. Applications should retry until true is returned. Safe to call
  *     again after true is returned.
  */
 public boolean publishInstall(final Context context) {
   try {
     // copy the application id to guarantee thread safety..
     String applicationId = mAppId;
     if (applicationId != null) {
       publishInstall(this, applicationId, context);
       return true;
     }
   } catch (Exception e) {
     // if there was an error, fall through to the failure case.
     Util.logd("Facebook-publish", e.getMessage());
   }
   return false;
 }