code: public void writeMasterPageStyles(final XMLUtil util, final Appendable appendable)
              throws IOException {
          for (final MasterPageStyle ps : this.masterPageStylesContainer.getValues()) {
              ps.appendXMLToMasterStyle(util, appendable);
          }
      }
docs: Write master page styles. The master page style always belong to to styles
  .xml/master-styles (3.15.4)
  
  @param util   an util
  @param appendable the destination
  @throws IOException if an I/O error occurs