Put bars in front of area

hello,
in charts which contain data of type bar and area, area always overlaps bars. The unwanted effect is the color change of the bar because of the area.
In C3.js if I change in `c3_chart_internal_fn.initChartElements` the order between `initBar` and `initLine` then areas are overlapped by bars. This has the side effect that now lines and circle also are oberlapped by bars. So my question is, cant we draw only the area in a `` before bar. So lines and circle would be visible but the area would only be visible in undrawn areas of the chart