Does GradientPaintTransformer work with StackedBarRenderer?

[rcdjbp]

I initially posted this on 26 JUL. I'm thinking it must be too dumb to bother with or too difficult to answer?
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I don't see the gradient when I use GradientPaintTransformer with StackedBarRenderer. I see it with BarRenderer.

StackedBarRenderer sbr = new StackedBarRenderer();
BarRenderer br = new BarRenderer();

I see the gradient with
br.setGradientPaintTransformer(new StandardGradientPaintTransformer GradientPaintTransformType.HORIZONTAL));

I do not see the gradient with
sbr.setGradientPaintTransformer(new StandardGradientPaintTransformer GradientPaintTransformType.HORIZONTAL));