code: private static JpaStorage initJpaStorage(ApiManagerConfig config, JpaStorage jpaStorage) {
          if (sJpaStorage == null) {
              sJpaStorage = jpaStorage;
              if (config.isInitializeStorageJPA()) {
                  JpaStorageInitializer initializer = new JpaStorageInitializer(config.getHibernateDataSource(), config.getHibernateDialect());
                  initializer.initialize();
              }
          }
          return sJpaStorage;
      }
docs: Initializes the JPA storage (if required).  This basically amounts to installing
  the DDL in the database.  This is optional and disabled by default.
  @param config
  @param jpaStorage