docs: public static String marshalToString(Object obj, String... fliterFields) {
          final List<String> propertyFliters = Arrays.asList(fliterFields);
          SerializeWriter out = new SerializeWriter();
          try {
              JSONSerializer serializer = new JSONSerializer(out);
              serializer.getPropertyFilters().add(new PropertyFilter() {
  
                  public boolean apply(Object source, String name, Object value) {
                      return !propertyFliters.contains(name);
                  }
  
              });
              serializer.write(obj);
              return out.toString();
          } finally {
              out.close();
          }
      }