Bar Chart - Percentage

Hi!
Great library, thanks for that! One thing that I would really like to see and that keeps me from using C3 for my upcoming project is the following: I would like scale stacked bar charts to 100%, loading in absulute numbers. Basically similar to pie/donut charts at the moment, where you load in the absolute numbers, the percentages of the pie get calculated but the tooltip still shows the absolute numbers. Highcharts has a function like this, where you can simply turn on "column: {stacking: 'percent'}" and each bar gets scaled to 100%. It would be great to have this - it would save me a lot of time converting all my project (which should go live really soon...) into Highcharts. Thanks so much!