public MapPlotResourceManager() {
   for (PlotLineStyle plotLineStyle : PlotLineStyle.values()) {
     for (PlotLineColor plotLineColor : PlotLineColor.values()) {
       preparedLineDefs.add(PlotLineDef.newInstance(plotLineColor.getColor(), plotLineStyle));
     }
   }
 }
 public PlotFunction(@Nonnull XyFunction xyFunction) {
   this.xyFunction = xyFunction;
   this.plotLineDef = PlotLineDef.newDefaultInstance();
 }