iAd: How to simulate errors?

In my didFailToReceiveAdWithError I want t开发者_运维百科o hide iAd banner and show banner from other ad provider.

How do I simulate error call?

Note: closing the internet connection is not an option since I still need it for the other ad provider.

Go into your settings -> Developer -> fill rate under iAd settings and select 0%.

You'll get errors regularly when running a test config. The service does this intentionally to help you test. You can also just call your didFailToRecieveAdWithError method from your didRecieveAd method.