EntityManager.getEntityGraph - get a root entity's object graph from cache
Like the FindEntityGraph method in DevForce (http://drc.ideablade.com/xwiki/bin/view/Documentation/query-working-in-cache), this method would return an array of entities in cache consisting of the root entity and the related entities as specified in the call, perhaps with "expand" syntax. Could use for partial saves as requested in this S.O. post (http://stackoverflow.com/questions/13575058/how-can-i-save-a-single-entity-with-entitymanagers-savechanges-method). Also useful for moving graphs between EntityManagers and to browser local storage.