code: private static void addCashFlowAxis(XYPlot plot, TimeSeriesCollection dataset) {
          final NumberAxis cashAxis = new NumberAxis("Cash Flow Ratio");
          cashAxis.setAutoRangeIncludesZero(false);
          plot.setRangeAxis(1, cashAxis);
          plot.setDataset(1, dataset);
          plot.mapDatasetToRangeAxis(1, 1);
          final StandardXYItemRenderer cashFlowRenderer = new StandardXYItemRenderer();
          cashFlowRenderer.setSeriesPaint(0, Color.blue);
          plot.setRenderer(1, cashFlowRenderer);
      }
docs: Adds the cash flow axis to the plot.
  @param plot the plot
  @param dataset the cash flow dataset