code: private void registerDefaultStyles() {
          defaultsLoaded = true;
          if(!this.styleMap.containsKey(RtfParagraphStyle.STYLE_NORMAL.getStyleName())) {
              registerParagraphStyle(RtfParagraphStyle.STYLE_NORMAL);
          }
          if(!this.styleMap.containsKey(RtfParagraphStyle.STYLE_HEADING_1.getStyleName())) {
              registerParagraphStyle(RtfParagraphStyle.STYLE_HEADING_1);
          }
          if(!this.styleMap.containsKey(RtfParagraphStyle.STYLE_HEADING_2.getStyleName())) {
              registerParagraphStyle(RtfParagraphStyle.STYLE_HEADING_2);
          }
          if(!this.styleMap.containsKey(RtfParagraphStyle.STYLE_HEADING_3.getStyleName())) {
              registerParagraphStyle(RtfParagraphStyle.STYLE_HEADING_3);
          }
      }
docs: Registers all default styles. If styles with the given name have already been registered,
  then they are NOT overwritten.