code: public void close() {
      for (Entry<String, OResourcePool<String, DB>> pool : pools.entrySet()) {
        for (DB db : pool.getValue().getResources()) {
          pool.getValue().close();
          try {
            OLogManager.instance().debug(this, "Closing pooled database '%s'...", db.getName());
            ((ODatabasePooled) db).forceClose();
            OLogManager.instance().debug(this, "OK", db.getName());
          } catch (Exception e) {
            OLogManager.instance().debug(this, "Error: %d", e.toString());
          }
        }
      }
    }
docs: Closes all the databases.