code: function(item) {
  		 	var itemToSelect = item || this.getItems()[0];
  		 	if (itemToSelect) {
  		 		if (this._selectedItem) {
  		 			this._selectedItem.classList.remove("dropdownMenuItemSelected"); //$NON-NLS-0$
  			 	}
  			 	this._selectedItem = itemToSelect;
  			 	this._selectedItem.classList.add("dropdownMenuItemSelected"); //$NON-NLS-0$	
  			 	this._selectedItem.focus();
  			 	if (this._buttonsAdded) {
  			 		var itemBounds = this._selectedItem.getBoundingClientRect();
  			 		var menuBounds = this._dropdownNode.getBoundingClientRect();
  			 		if (this._selectedItem.offsetTop < this._dropdownNode.scrollTop) {
  		 				this._selectedItem.scrollIntoView(true);
  		 				if (this._dropdownNode.scrollTop < 5) {
  		 					this._dropdownNode.scrollTop = 0;
  		 				}
  		 			}
  		 			else if (itemBounds.bottom > menuBounds.bottom) {
  		 				this._selectedItem.scrollIntoView(false);
  		 				if ((this._dropdownNode.scrollHeight - this._dropdownNode.scrollTop - this._dropdownNode.clientHeight) < 5) {
  		 					this._dropdownNode.scrollTop = this._dropdownNode.scrollHeight - this._dropdownNode.clientHeight;
  		 				}
  		 			}
  		 			updateScrollButtonVisibility.call(this);
  				}
  		 	}
  		 }
docs: Selects the specified dropdown menu item or the first
  dropdown menu item if none is specified.
  @param {Object} item The dropdown menu item that should be selected. See @ref getItems() for details. Optional.