public RewardVideoClient(string adAppId, string adUnitId)
 {
     rewardVideoClientPtr = (IntPtr)GCHandle.Alloc(this);
     RewardVideoPtr       = Externs.ZPLADCreateRewardVideo(rewardVideoClientPtr, adAppId, adUnitId);
     Externs.ZPLADSetRewardVideoAdCallbacks(
         rewardVideoPtr,
         RewardVideoDidReceivedAdCallback,
         RewardVideoDidFailToReceiveAdWithErrorCallback,
         RewardVideoVideoDidStartPlayingCallback,
         RewardVideoDidClickCallback,
         RewardVideoDidRewardCallback,
         RewardVideoVideoDidCloseCallback,
         RewardVideoDidCompleteCallback
         );
 }