public override void InterstitialDidLoadAd(MPInterstitialAdController interstitial)
 {
     Console.WriteLine("Loading interstitials with AdUnitID = " + interstitial.AdUnitId);
     interstitial.ShowFromViewController(controller);
 }
 public override void InterstitialDidLoadAd(MPInterstitialAdController interstitial)
 {
     Console.WriteLine ("Loading interstitials with AdUnitID = " + interstitial.AdUnitId);
     interstitial.ShowFromViewController (controller);
 }