docs: public String encode() throws IOException {
          FastStringWriter fsw = new FastStringWriter();
  
          try {
              fsw.write("{");
  
              ChartUtils.writeDataValue(fsw, "display", this.display, false);
              ChartUtils.writeDataValue(fsw, "color", this.color, true);
              ChartUtils.writeDataValue(fsw, "lineWidth", this.lineWidth, true);
  
              fsw.write("}");
          }
          finally {
              fsw.close();
          }
  
          return fsw.toString();
      }