code: function (aButtons) {
  			for (var i = aButtons.length - 1; i >= 0; i--) {
  				if (aButtons[i].getVisible()) {
  					aButtons[i].setVisible(false);
  					this.addOverflowButton();
  					return;
  				}
  			}
  		}
docs: Hides the last visible button and adds an OverflowButton
  @param {array} aButtons some buttons