code: private JAXBContext getSingleton() throws JAXBException {
          if (jcSingelton == null) {
              ClassLoader classLoader = ch.epfl.bbp.uima.xml.genia.ObjectFactory.class
                      .getClassLoader();// TODO needed?
              jcSingelton = JAXBContext.newInstance(Set.class.getPackage()
                      .getName(), classLoader);
          }
          return jcSingelton;
      }
docs: Use singleton design pattern, since JAXBContext is expensive to create