code: @Override
      public void removedBundle(Bundle bundle, BundleEvent event, List<I18nExtension> list) {
          String current = Long.toString(System.currentTimeMillis());
          for (I18nExtension extension : list) {
              synchronized (this) {
                  extensions.remove(extension);
                  etags.put(extension.locale(), current);
              }
          }
          LOGGER.info("Bundle {} ({}) does not offer the {} resource bundle(s) anymore",
                  bundle.getSymbolicName(), bundle.getBundleId(), list.size());
      }
docs: A bundle tracked by the {@code BundleTracker} has been removed.
  <p/>
  <p/>
  This method is called after a bundle is no longer being tracked by the
  {@code BundleTracker}.
  
  @param bundle The {@code Bundle} that has been removed.
  @param event  The bundle event which caused this customizer method to be
  called or {@code null} if there is no bundle event associated
  with the call to this method.
  @param list   The tracked object for the specified bundle.