How do i implement vungle in to corona sdk for only one scene. I followed the docs on corona site to implement vungle to my game. I implemented in only one scene of my game but it shows in every scene randomly, my question is how do i keep the vungle in only one scene. 

I use also inmobi ads in game. 

Here is the code i used.

I used this code in only one scene of my game.

```
 local provider = "vungle"
 local appId = "vungleTest"
 local ads = require "ads"

 local function adListener( event )
    if event.type == "adStart" and event.isError then
        -- cached video ad not available for display
    end
 end

 ads.init( provider, appId, adListener )
 local wasAdShown = ads.show( "interstitial", { isAnimated = false, isBackButtonEnabled = true } )

```