code: public String printDefaultValue() {
          if (setter instanceof Getter) {
              Getter getter = (Getter)setter;
              List<T> defaultValues = getter.getValueList();
  
              StringBuilder buf = new StringBuilder();
              for (T v : defaultValues) {
                  if (buf.length()>0)     buf.append(delimiter);
                  buf.append(print(v));
              }
              return buf.toString();
          }
          return null;
      }
docs: Prints the default value by introspecting the current setter as {@link Getter}.
  
  @return null if the current value of the setter isn't available.