Ability to have multiple "stacked" charts

Right now, if you use a stacked chart, all the data for each "X" entry is added to a single stacked column.

I would like to have 2 or more, stacked charts.

For instance, say you had a chart of Bugs over Time

You might have Bugs & suggestions in one "stacked column". And "Fixed bugs & Fixed Suggestions) in the adjacent stacked column, as a pair for each X axis