Clearing indices for unit testing with Appengine Java Search API

Despite its limitations, we still use the Google AppEngine Java Search API in some of our products. In working on some unit tests, I became aware that the search indices are persisted across tests. Aside from the brute force approach of manually clearing the indices, is anyone aware of built in support for unit testing - e.g. starting with a clean slate for each unit test? I wasn't able to find anything in the documentation. Thanks!