Каким-то образом я упустил это из примера :
GDataServiceGoogleDocs *service = [self docsService];
NSURL *entryURL = [GDataServiceGoogleDocs metadataEntryURLForUserID:kGDataServiceDefaultUser];
GDataServiceTicket *ticket;
ticket = [service fetchEntryWithURL:entryURL
delegate:self
didFinishSelector:@selector(metadataFeedTicket:finishedWithEntry:error:)];