getRendererInstance(XYPlot plot)
Not completely sure why this is necessary, but if it's not here then
subclasses are forced to take a Plot instead of an XYPlot as a parameter,
which in turn breaks the pattern.
Not completely sure why this is necessary, but if it's not here then
subclasses are forced to take a Plot instead of an XYPlot as a parameter,
which in turn breaks the pattern.