joinTableData.addJoinTableRecord(joinKey, inverseJoinKeys);
EntityManager em = emf.createEntityManager();
Map<String, Client> clients = (Map<String, Client>) em.getDelegate();
CouchDBClient client = (CouchDBClient) clients.get(_PU);
client.persistJoinTable(joinTableData);
List<String> columns = client.getColumnsById(schemaName, tableName, joinColumn, inverseJoinColumn, joinKey,
String.class);
Assert.assertNotNull(columns);