code: @Override
      public void onPluginEvent(PluginEvent event) {
          ElementPlugin plugin = event.getPlugin();
          
          switch (event.getAction()) {
              case SUBSCRIBE:
                  init();
                  plugins.add(plugin);
                  plugin.setDisabled(isDisabled());
                  break;
              
              case UNSUBSCRIBE:
                  plugins.remove(plugin);
                  plugin.setDisabled(false);
                  break;
          }
      }
docs: Subscribe/unsubscribe container.