How to add negative values to JavaFx Area Chart?

Question

I'd like to draw a difference (area) chart, something like this: How would d3.js difference chart example work with json data? where my chart is centered around horizontal (y=0) axis.

JavaFx's Area chart seems to know how to fill only the area below the line!?

Example "Adding negative value" (Fig 33-7) seems to be what I'm looking for (March series) BUT it does not work/render as shown!

Instead of:

it renders:

Thanks,

Igor