code:     public void destroy() {
          normalView = null;
          viewViews = null;
          viewServers = null;
          viewGraphs = null;
          pageView = null;
          editView = null;
          addView = null;
          addGraph = null;
          editGraph = null;
          viewServer = null;
          editServer = null;
          addServer = null;
          helpView = null;
          editNormalView = null;
          super.destroy();
      }
  