code: public List<IAtomType> readAtomTypes(IChemObjectBuilder builder) {
          List<IAtomType> isotopes = new ArrayList<IAtomType>();
          try {
              parser.setFeature("http://xml.org/sax/features/validation", false);
              logger.info("Deactivated validation");
          } catch (SAXException exception) {
              logger.warn("Cannot deactivate validation: ", exception.getMessage());
              logger.debug(exception);
          }
          AtomTypeHandler handler = new AtomTypeHandler(builder);
          parser.setContentHandler(handler);
          try {
              parser.parse(new InputSource(input));
              isotopes = handler.getAtomTypes();
          } catch (IOException exception) {
              logger.error("IOException: ", exception.getMessage());
              logger.debug(exception);
          } catch (SAXException saxe) {
              logger.error("SAXException: ", saxe.getMessage());
              logger.debug(saxe);
          }
          return isotopes;
      }
docs: Reads the atom types from the data file.
  
  @param  builder The IChemObjectBuilder used to create new IAtomType's.
  @return         a List with atom types. Is empty if some reading error occurred.