code: public void writeHiddenDataStyles(final XMLUtil util, final Appendable appendable)
              throws IOException {
          for (final DataStyle dataStyle : this.dataStylesContainer
                  .getValues(Dest.CONTENT_AUTOMATIC_STYLES)) {
              dataStyle.appendXMLContent(util, appendable);
          }
      }
docs: Write the data styles in the automatic-styles. They belong to content.xml/automatic-styles
  
  @param util   an XML util
  @param appendable the destination
  @throws IOException if the styles can't be written