Android, AppBrain AppLift SDK: how to add event handler on interstitial ad click

Android, AppBrain AppLift SDK: how to add event handler on interstitial ad
click

I have an Android app and I'm adding AppBrain SDK to show AppBrain's offer
wall (list of apps advertisied on AppBrain), which I consider less
annoying than other types of full-screen ads. I implemented AppBrain's
AppLift SDK and it shows the offer wall. I would like to [do something]
when a user clicks on one of the ads shown on the offer wall (nothing
malicious, just some tracking for statistical purposes). They do have
examples on using both regular ads and full-screen ads, but only regular
banner ads example shows how to use BannerListener to handle onclick,
onshow, etc. The example for interstitial ads does not have anything on
the use of BannerListener, and I can't figure out how to tie it to the
AdService class which is what's used to server interstitial ads:
AppBrain.init(this);
AdService ads = AppBrain.getAds();
ads.maybeShowInterstitial(this);
Their support did not respond to my email, so I thought I'd ask here. Any
ideas/comments/suggestions will be greatly appreciated!