Prevent adding shadow to tableview from allowing hidden rows to show through in Objective-C or Swift

Question

I am adding a shadow to a tableview using the following code. In general, my understanding is you have to set clipsToBounds or masksToBounds to NO to add the shadow.

-(void)addShadowToView:(UIView*) tv {
   tv.layer.shadowColor = [UIColor darkGrayColor].CGColor;
   tv.layer.shadowOffset = CGSizeMake(-15, 5);
    tv.layer.shadowRadius = 5;
    tv.layer.shadowOpacity = 0.5;
  // tv.clipsToBounds = NO;
    tv.layer.masksToBounds = NO;
}

However, the above code is having the undesired side effect of letting an otherwise hidden row of the table display below it as in the attached picture. Without setting either clipsToBounds or masksToBounds to NO, the shadow does not appear at all.

How can I add a shadow to a tableview without running into this unexpected issue.

Thanks in advance for any suggestions.