code: function (p_oElement, p_oAttributes) {
          
              this._buttons = [];
          
              YAHOO.widget.ButtonGroup.superclass.init.call(this, p_oElement, 
                      p_oAttributes);
          
              this.addClass(this.CLASS_NAME_PREFIX + this.CSS_CLASS_NAME);
  
          
              var sClass = (YAHOO.widget.Button.prototype.CLASS_NAME_PREFIX + "radio-button"),
  				aButtons = this.getElementsByClassName(sClass);
  
          
          
              if (aButtons.length > 0) {
          
          
                  this.addButtons(aButtons);
          
              }
          
          
          
              function isRadioButton(p_oElement) {
          
                  return (p_oElement.type == "radio");
          
              }
          
              aButtons = 
                  Dom.getElementsBy(isRadioButton, "input", this.get("element"));
          
          
              if (aButtons.length > 0) {
          
          
                  this.addButtons(aButtons);
          
              }
          
              this.on("keydown", this._onKeyDown);
              this.on("appendTo", this._onAppendTo);
          
  
              var oContainer = this.get("container");
  
              if (oContainer) {
          
                  if (Lang.isString(oContainer)) {
          
                      Event.onContentReady(oContainer, function () {
          
                          this.appendTo(oContainer);            
                      
                      }, null, this);
          
                  }
                  else {
          
                      this.appendTo(oContainer);
          
                  }
          
              }
          
          
          
          }
docs: Public methods 
  @method init
  @description The ButtonGroup class's initialization method.
  @param {String} p_oElement String specifying the id attribute of the
  <code>&#60;div&#62;</code> element of the button group.
  @param {<a href="http://www.w3.org/TR/2000/WD-DOM-Level-1-20000929/
  level-one-html.html#ID-22445964">HTMLDivElement</a>} p_oElement Object
  specifying the <code>&#60;div&#62;</code> element of the button group.
  @param {Object} p_oElement Object literal specifying a set of
  configuration attributes used to create the button group.
  @param {Object} p_oAttributes Optional. Object literal specifying a
  set of configuration attributes used to create the button group.