code: @SuppressWarnings("unchecked")
      private UNode optionValueToUNode(String optName, Object optValue) {
          if (!(optValue instanceof Map)) {
              if (optValue == null) {
                  optValue = "";
              }
              return UNode.createValueNode(optName, optValue.toString(), "option");
          }
          UNode optNode = UNode.createMapNode(optName, "option");
          Map<String, Object> suboptMap = (Map<String,Object>)optValue;
          for (String suboptName : suboptMap.keySet()) {
              optNode.addChildNode(optionValueToUNode(suboptName, suboptMap.get(suboptName)));
          }
          return optNode;
      }
docs: Return a UNode that represents the given option's serialized value.