I would expect this code to create a border with a bottom red line. It doesn't. It doesn't create a border at all.
I don't know if it is a bug in the Border code or if I'm supposed to use the API in a difference way.

new Border(new BorderStroke(Color.RED, BorderStrokeStyle.SOLID, CornerRadii.EMPTY, new BorderWidths(0, 0, 1, 0)))

The API and JavaDoc needs to be improved.

The API needs to at least make it trivial to create something like the Swing MatteBorder.