code: public RadarSeries addSeries(String seriesName, double[] values, String[] tooltipOverrides) {
  
      // Sanity checks
      sanityCheck(seriesName, values, tooltipOverrides);
  
      RadarSeries series = new RadarSeries(seriesName, values, tooltipOverrides);
  
      seriesMap.put(seriesName, series);
  
      return series;
    }
docs: Add a series for a Radar type chart
  
  @param seriesName
  @param values
  @param tooltipOverrides
  @return