js/libs/ember-1.5.1.js
function(name, value) {
    var attributes = this.elementAttributes = (this.elementAttributes || {});

    if (arguments.length === 1) {
      return attributes[name];
    } else {
      attributes[name] = value;
    }

    return this;
  }
function(name, value) {
    var attributes = this.elementAttributes = (this.elementAttributes || {});

    if (arguments.length === 1) {
      return attributes[name];
    } else {
      attributes[name] = value;
    }

    return this;
  }
duck type attribute functionality like jQuery so a render buffer can be used like a jQuery object in attribute binding scenarios. 
Adds an attribute which will be rendered to the element.

@method attr
@param {String} name The name of the attribute
@param {String} value The value to add to the attribute
@chainable
@return {Ember.RenderBuffer|String} this or the current attribute value