void Start()
  {
 AdMobRewardedAd = RewardBasedVideoAd.Instance;
 // Called when an ad request has successfully loaded.
 AdMobRewardedAd.OnAdLoaded += HandleRewardBasedVideoLoaded;
 // Called when an ad request failed to load.
 AdMobRewardedAd.OnAdFailedToLoad += HandleRewardBasedVideoFailedToLoad;
 // Called when an ad is shown.
 AdMobRewardedAd.OnAdOpening += HandleRewardBasedVideoOpened;
 // Called when the ad starts to play.
 AdMobRewardedAd.OnAdStarted += HandleRewardBasedVideoStarted;
 // Called when the user should be rewarded for watching a video.
 AdMobRewardedAd.OnAdRewarded += HandleRewardBasedVideoRewarded;
 // Called when the ad is closed.
 AdMobRewardedAd.OnAdClosed += HandleRewardBasedVideoClosed;
 // Called when the ad click caused the user to leave the application.
 AdMobRewardedAd.OnAdLeavingApplication += HandleRewardBasedVideoLeftApplication;
// Initialize the Google Mobile Ads SDK.
 MobileAds.Initialize(appId);

 this.Load_rewarded_video();
}
//Google ad mob Handlers======================
public void HandleRewardBasedVideoLoaded(object sender, EventArgs   args)
{
 //MonoBehaviour.print("HandleRewardBasedVideoLoaded event received");
}
 public void HandleRewardBasedVideoFailedToLoad(object sender, AdFailedToLoadEventArgs args)
{
 Time.timeScale = 1;
 //MonoBehaviour.print(
 //    "HandleRewardBasedVideoFailedToLoad event received with      message: "
 //                     + args.Message);
 }
public void HandleRewardBasedVideoOpened(object sender, EventArgs args)
{
 //MonoBehaviour.print("HandleRewardBasedVideoOpened event received");
}
public void HandleRewardBasedVideoStarted(object sender, EventArgs args)
{
 //MonoBehaviour.print("HandleRewardBasedVideoStarted event received");
}
public void HandleRewardBasedVideoClosed(object sender, EventArgs args)
{
 //MonoBehaviour.print("HandleRewardBasedVideoClosed event received");
 Time.timeScale = 1;

 this.Load_rewarded_video();

 }
 public void HandleRewardBasedVideoRewarded(object sender, Reward args)
 {
 Time.timeScale = 1;
 ContinueGameCalculations();
 }
 public void HandleRewardBasedVideoLeftApplication(object sender, EventArgs args)
 {
 //MonoBehaviour.print("HandleRewardBasedVideoLeftApplication event received");
  }
  private void Load_rewarded_video()
  {
  #if UNITY_IOS
 string ad_unit = "ca-app-pub-5759662936419616/3614417629";
 #endif
 AdMobRewardedAd.LoadAd(new AdRequest.Builder().Build(), ad_unit);
 }