/**
  * Feature installers registered automatically when auto scan enabled, but if you don't want to
  * use it, you can register installers manually (note: without auto scan default installers will
  * not be registered).
  *
  * <p>Also, could be used to add installers from packages not included in auto scanning.
  *
  * @param installers feature installer classes to register
  * @return configurer instance for chained calls
  */
 @SafeVarargs
 public final GuiceyBootstrap installers(final Class<? extends FeatureInstaller>... installers) {
   installerConfig.getManualFeatures().addAll(Arrays.asList(installers));
   return this;
 }