LinkedHashSet<YAxis> yAxesSet = new LinkedHashSet<InvientChartsConfig.YAxis>();
yAxesSet.add(temperatureAxis);
// secondary y-axis
NumberYAxis rainfallAxis = new NumberYAxis();
rainfallAxis.setGrid(new Grid());
rainfallAxis.getGrid().setLineWidth(0);
rainfallAxis.setTitle(new AxisTitle("Rainfall"));
rainfallAxis.getTitle().setStyle(" { color: '#4572A7' }");
rainfallAxis.setLabel(new YAxisDataLabel());
rainfallAxis.getLabel().setStyle("{ color: '#4572A7' }");
rainfallAxis.getLabel().setFormatterJsFunc(
"function() {" + " return this.value +' mm'; " + "}");
yAxesSet.add(rainfallAxis);
// tertiary y-axis
NumberYAxis sealevelPressureAxis = new NumberYAxis();
sealevelPressureAxis.setGrid(new Grid());
sealevelPressureAxis.getGrid().setLineWidth(0);
sealevelPressureAxis.setTitle(new AxisTitle("Sea-Level Pressure"));
sealevelPressureAxis.getTitle().setStyle(" { color: '#AA4643' }");
sealevelPressureAxis.setLabel(new YAxisDataLabel());
sealevelPressureAxis.getLabel().setStyle("{ color: '#AA4643' }");