docs: public String encode() throws IOException {
          FastStringWriter fsw = new FastStringWriter();
  
          try {
              fsw.write("{");
  
              ChartUtils.writeDataValue(fsw, "display", this.display, false);
              ChartUtils.writeDataValue(fsw, "labelString", this.labelString, true);
              ChartUtils.writeDataValue(fsw, "lineHeight", this.lineHeight, true);
              ChartUtils.writeDataValue(fsw, "fontColor", this.fontColor, true);
              ChartUtils.writeDataValue(fsw, "fontFamily", this.fontFamily, true);
              ChartUtils.writeDataValue(fsw, "fontSize", this.fontSize, true);
              ChartUtils.writeDataValue(fsw, "fontStyle", this.fontStyle, true);
              ChartUtils.writeDataValue(fsw, "padding", this.padding, true);
  
              fsw.write("}");
          }
          finally {
              fsw.close();
          }
  
          return fsw.toString();
      }