LinkedHashSet<YAxis> yAxesSet = new LinkedHashSet<InvientChartsConfig.YAxis>();
yAxesSet.add(yAxis);
chartConfig.setYAxes(yAxesSet);
Tooltip tooltip = new Tooltip();
tooltip.setFormatterJsFunc("function() {"
+ " return '<b>'+ this.series.name +', age '+ this.point.category +'</b><br/>' + "
+ " 'Population: '+ Highcharts.numberFormat(Math.abs(this.point.y), 0); "
+ "}");
SeriesConfig series = new SeriesConfig();