How get app key in API 2?

In API 1, I could get the app key like this:

NSString *cachedAppKey = ...
MPOAuthCredentialConcreteStore *store = [[DBSession sharedSession] credentialStoreForUserId:nil];
if (cachedAppKey == nil || [cachedAppKey isEqualToString:store.consumerKey] == NO)
{
    NSLog (@"App key changed since last use!", nil);
}

Is there a way of doing this in API 2?

The reason I do this is to check that the app hasn't had to change its app key for some reason, which would mess up delta keys for -listFolderContinue:. It's a bit of an edge-case, and the code is really only there because I had to switch between an app folder key and a full access key during beta-testing, so had to ensure an invalid delta value wasn't used after the change-over.

Thanks,

Keith

EDIT: Actually, I suppose I can just get it from the info.plist file directly, removing the "db-" prefix.