docs: function () {
  
              var that = this;
              var now = +new Date();
              var toRemove = _(this.controllers).filter(function (c) {
                  var age = (now - c.lastView);
                  return (age > 60000); // Keep in cache for 1 minute.
              });
  
              _(toRemove).each(function (c) {
                  if (c.controller !== that.currentController) {
                      delete that.controllers[c.pageUID];
                      c.controller.destroy();
                      if (c.controller._rootView) {
                          c.controller._rootView.clean();
                          c.controller._rootView.remove();
                          Jackbone.trigger("destroyview", c.controller._rootView);
                      }
                  }
              });
          }