code: function (group) {
  				var stackItem = this,									// aliased this
  					str = stackItem.options.formatter.call(stackItem);	// format the text in the label
  
  				// Change the text to reflect the new total and set visibility to hidden in case the serie is hidden
  				if (stackItem.label) {
  					stackItem.label.attr({text: str, visibility: HIDDEN});
  				// Create new label
  				} else {
  					stackItem.label =
  						chart.renderer.text(str, 0, 0)				// dummy positions, actual position updated with setOffset method in columnseries
  							.css(stackItem.options.style)			// apply style
  							.attr({align: stackItem.textAlign,			// fix the text-anchor
  								rotation: stackItem.options.rotation,	// rotation
  								visibility: HIDDEN })					// hidden until setOffset is called
  							.add(group);							// add to the labels-group
  				}
  			}
docs: Renders the stack total label and adds it to the stack label group.