javascript - How can I set properties for ui Backbone element? -

how can set properties (attributes) "uploadbutton"?

return marionette.itemview.extend({   ui: {        "uploadbutton": "ui-button green"     } });  this.ui.uploadbutton. - and??? 

unless marionette odd, backbone way of doing is

return marionette.itemview.extend({   attributes: {     width: "500"   },   ui: {      "uploadbutton": "ui-button green"   } });