drawTrackerWrapper = function (proceed) {
			proceed.call(this);
			each(this.points, function (point) {
				if (point.drilldown && point.graphic) {
					point.graphic
						.attr({
							'class': 'highcharts-drilldown-point'
						})
						.css({ cursor: 'pointer' });
				}
			});
		}
When drilling up, pull out the individual point graphics from the lower series
and animate them into the origin point in the upper series.