// draw the shared axis
CategoryAxis axis = getDomainAxis();
RectangleEdge domainEdge = getDomainAxisEdge();
double cursor = RectangleEdge.coordinate(dataArea, domainEdge);
AxisState axisState = axis.draw(g2, cursor, plotArea, dataArea, domainEdge, info);
if (parentState == null) {
parentState = new PlotState();
}
parentState.getSharedAxisStates().put(axis, axisState);