code: public final void onRefreshEvent(RefreshEvent event) {
          Map<String, Object> changes = event.getSource();
          if (changes == RefreshEvent.ALL_KEYS) {
              disposeOfAllBeans();
              refreshAllConfigurationProperties();
          } else {
              disposeOfBeanSubset(changes.keySet());
              refreshSubsetOfConfigurationProperties(changes.keySet());
          }
      }
docs: Handle a {@link RefreshEvent} synchronously. This method blocks unlike {@link #onApplicationEvent(RefreshEvent)}.
  
  @param event The event