code: public static MonomerStore getMonomerStore(Element rootElement)
        throws MonomerException, IOException {
      MonomerStore monomerStore = new MonomerStore();
      Element monomerListElement = rootElement.getChild("Monomers");
      if (monomerListElement != null) {
        @SuppressWarnings("unchecked")
        List<Element> elementList = monomerListElement.getChildren("Monomer");
  
        for (Element monomerElement : elementList) {
          Monomer m = MonomerParser.getMonomer(monomerElement);
          monomerStore.addMonomer(m);
        }
      }
      return monomerStore;
    }
docs: Generates the monomer store from a given XHELM document
  
  @param rootElement root element
  @return a monomer store
  @throws MonomerException if monomer is not valid
  @throws IOException IO error