title: No interface method onVideoCompleted in MediationRewardedVideoAdListener class
body: <p>I'm facing a problem that drives me crazy
  i have setup a reward video on my game .</p>
  
  <p>I have implemended a rewardedvideolistener and everything is working as they should , as long as i use admob only as my source of reward videos.
  Now i have added a mediation networks (tapjoy)
  I'm able to see the video rewards but as soon as the video ends i am getting an error that i am unable to understand how to implement
  <a href="https://i.stack.imgur.com/A2Sqq.png" rel="nofollow noreferrer">here is an image for the error</a></p>
  
  <p>java.lang.NoSuchMethodError: No interface method onVideoCompleted(Lcom/google/android/gms/ads/reward/mediation/MediationRewardedVideoAdAdapter;)V in class Lcom/google/android/gms/ads/reward/mediation/MediationRewardedVideoAdListener; or its super classes (declaration of 'com.google.android.gms.ads.reward.mediation.MediationRewardedVideoAdListener' appears in /data/app/com.moustafa.livematchesresults-2/base.apk)
                        at com.google.ads.mediation.tapjoy.TapjoyAdapter$7.run(TapjoyAdapter.java:472)
                        at android.os.Handler.handleCallback(Handler.java:739)
                        at android.os.Handler.dispatchMessage(Handler.java:95)
                        at android.os.Looper.loop(Looper.java:158)
                        at android.app.ActivityThread.main(ActivityThread.java:7231)
                        at java.lang.reflect.Method.invoke(Native Method)
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)</p>
  
  <p>thanks in advance!</p>