code: public UNode toUNode() {
          UNode rootNode = UNode.createMapNode("commands");
          for (String ownerName : m_cmdsByOwnerMap.keySet()) {
              Map<String, RESTCommand> ownerMap = m_cmdsByOwnerMap.get(ownerName);
              UNode ownerNode = rootNode.addMapNode(ownerName, "owner");
              for (String cmdName : ownerMap.keySet()) {
                  RESTCommand cmd = ownerMap.get(cmdName);
                  ownerNode.addChildNode(cmd.toDoc());
              }
          }
          return rootNode;
      }
docs: Serialize this RESTCatalog into a UNode tree and return the root node. The UNode
  tree can be serialized into into JSON or XML using {@link UNode#toJSON()} or
  {@link UNode#toXML()}.
  
  @return  Root node of the serialized {@link UNode} tree.