I have a contract with ad network for 1 position on my site. They gave me creatives (script). But sometimes they don't show any comercial. The script is running, but it returns an empty `iframe`. `iframe` height is 0. 
 
Still, the position is reserved and Adsense does not replace empty `iframe`.
I put order with Sponsor tag, third party creative, no labels. 
 
Can I somehow, with DFP,  menage this to maximize my profit? In other words, can I set up my position in a way that if creative does not have an ad to show ->show adsense instead.