code: function (ui, done) {
  
          var elems = ui.pluginManager.hook("elements");
          var bs    = ui.bs;
  
          if (!Object.keys(elems).length) {
              return done();
          }
  
          ui.setOption("clientFiles", Immutable.fromJS(elems));
  
          done(null, {
              instance: {
                  enableElement:  require("./client-elements").enable(ui.clients, ui, bs),
                  disableElement: require("./client-elements").disable(ui.clients, ui, bs),
                  addElement:     require("./client-elements").addElement
              }
          });
      }
docs: Allow an API for adding/removing elements to clients
  @param ui
  @param done