code: public OHLCSeries addSeries(
        String seriesName,
        List<?> xData,
        List<? extends Number> openData,
        List<? extends Number> highData,
        List<? extends Number> lowData,
        List<? extends Number> closeData) {
  
      DataType dataType = getDataType(xData);
      switch (dataType) {
        case Date:
          return addSeries(
              seriesName,
              Utils.getDoubleArrayFromDateList(xData),
              Utils.getDoubleArrayFromNumberList(openData),
              Utils.getDoubleArrayFromNumberList(highData),
              Utils.getDoubleArrayFromNumberList(lowData),
              Utils.getDoubleArrayFromNumberList(closeData),
              DataType.Date);
  
        default:
          return addSeries(
              seriesName,
              Utils.getDoubleArrayFromNumberList(xData),
              Utils.getDoubleArrayFromNumberList(openData),
              Utils.getDoubleArrayFromNumberList(highData),
              Utils.getDoubleArrayFromNumberList(lowData),
              Utils.getDoubleArrayFromNumberList(closeData),
              DataType.Number);
      }
    }
docs: Add a series for a OHLC type chart using Lists
  
  @param seriesName
  @param xData the x-axis data
  @param openData the open data
  @param highData the high data
  @param lowData the low data
  @param closeData the close data
  @return A Series object that you can set properties on