code: public static String getString() {
      final StringBuilder buf = new StringBuilder();
      buf.append("Feature List:\n");
      for (Feature f : Feature.values()) {
        buf.append(f).append(" introduced in layout version ")
            .append(f.lv).append(" (").
        append(f.description).append(")\n");
      }
      
      buf.append("\n\nLayoutVersion and supported features:\n");
      for (Feature f : Feature.values()) {
        buf.append(f.lv).append(": ").append(map.get(f.lv))
            .append("\n");
      }
      return buf.toString();
    }
docs: Gets formatted string that describes {@link LayoutVersion} information.