Search Ads attribution API: where to find the specification of response object (version 3.1)

I love the new Search Ads and I started using the "Search Ads attribution API" in my Xcode project.

Based on WWDC 2016 video I added following Obj-C code:

[[ADClient sharedClient] requestAttributionDetailsWithBlock:^(NSDictionary *attributionDetails, NSError *error) {
    if (error) {
        NSLog(@"Request Search Ads attributes failed with error: %@", error.description);
   
        if (error.code == ADClientErrorLimitAdTracking) {
            NSLog(@"Limit Ad Tracking is enabled for this device.");
        }
    }
    else {
        NSLog(@"Search Ads attributes: %@", attributionDetails);
    }
}];

It currently returns test data when using this code on device:

2016-09-29 13:25:09.107 _block_invoke line 48 $ Search Ads attributes: {

"Version3.1" = {

"iad-attribution" = true;

"iad-campaign-id" = 1234567890;

"iad-campaign-name" = CampaignName;

"iad-click-date" = "2016-09-29T11:25:08Z";

"iad-conversion-date" = "2016-09-29T11:25:08Z";

"iad-creative-id" = 1234567890;

"iad-creative-name" = CreativeName;

"iad-lineitem-id" = 1234567890;

"iad-lineitem-name" = LineName;

"iad-org-name" = OrgName;

};

}

However, this object contains different keys than in the WWDC video: while mentioning the same version 3.1:

For example "iad-click-date" vs. "iad-conversion-date". And the 2 "iad-lineitem-***" that are not mentioned in the video.

Where can I find the offical documentation or specification of the response object?

And what do they mean? Most are obvious, but I don't understand the "iad-lineitem-***" keys.

My current guess is that the response always contains the "iad-attribution" key. When it's false, the user hasn't tapped your ad before installing your app, and all other keys are either empty or non-existing.

Any help would be appreciated.

Thank you.