com.atlassian.jira.user.preferences.UserPreferenceManager.clearCache(String username) no longer works

It looks like the implementation of com.atlassian.jira.user.preferences.DefaultUserPreferenceManager changed between 5.0 and 5.1 and the 5.1 version now uses a com.google.common.cache.Cache instead of org.apache.commons.collections.map.LRUMap. This has changed the key for cache from the com.atlassian.crowd.embedded.api.User.getName() to com.atlassian.crowd.embedded.api.User. The API for UserPreferencesManager still takes a String instead of a com.atlassian.crowd.embedded.api.User for the clearCache(String username) method.

The only option now is to use clearCache() method but that clears the entire cache.

The UserPreferencesManager API needs to be updated.