code: public BubbleSeries addSeries(
        String seriesName, double[] xData, double[] yData, double[] bubbleData) {
  
      // Sanity checks
      sanityCheck(seriesName, xData, yData, bubbleData);
  
      BubbleSeries series;
      if (xData != null) {
  
        // Sanity check
        if (xData.length != yData.length) {
          throw new IllegalArgumentException("X and Y-Axis sizes are not the same!!!");
        }
  
        series = new BubbleSeries(seriesName, xData, yData, bubbleData);
      } else { // generate xData
        series =
            new BubbleSeries(
                seriesName, Utils.getGeneratedDataAsArray(yData.length), yData, bubbleData);
      }
  
      seriesMap.put(seriesName, series);
  
      return series;
    }
docs: Add a series for a Bubble type chart using using Lists
  
  @param seriesName
  @param xData the X-Axis data
  @param xData the Y-Axis data
  @param bubbleData the bubble data
  @return