code: public UNode toDoc() {
          // Root node is called "doc".
          UNode result = UNode.createMapNode("doc");
          
          // Each child of "doc" is a simple VALUE node.
          for (String fieldName : m_resultFields.keySet()) {
              // In XML, we want the element name to be "field" when the node name is "_ID".
              if (fieldName.equals(OBJECT_ID)) {
                  result.addValueNode(fieldName, m_resultFields.get(fieldName), "field");
              } else {
                  result.addValueNode(fieldName, m_resultFields.get(fieldName));
              }
          }
          return result;
      }
docs: Serialize this ObjectResult into a UNode tree. The root node is called "doc".
  
  @return  This object serialized into a UNode tree.