Feature Request: Show No data message but with legend for empty column.

I have managed to display "No data available message" on my chart. But trouble is that I want to show legend with data name even when there is no data.

If the values are null, the "No data" message will disappear. If there is no data, message will appear but legend will disappear.

I have made a fiddle here https://stackoverflow.com/questions/47712087/how-to-show-c3-js-no-data-but-with-legend-for-empty-column/