code: void registerKnownDrivers() {
      if (appConfig.allowedDrivers == null) {
        return;
      }
      for (String driverName : appConfig.allowedDrivers) {
        try {
          Class.forName(driverName);
        } catch (Throwable t) {
          // ignore
        }
      }
    }
docs: Walk through all the known drivers and try to register them.