If you plan to migrate existing ads to Expanded Text Ads using AdGroupService, you might be limited by the
operational limits associated with your developer token. You might also encounter
RateExceededError if you make a large number of requests per second on a single AdWords account.
BatchJobService is a better option to process large numbers of operations. If using BatchJobService is not an option, you can consider some strategies listed
here to mitigate RateExceededErrors.