code: public static RESTCatalog fromUNode(UNode rootNode) {
          RESTCatalog cmdSet = new RESTCatalog();
          Utils.require(rootNode.getName().equals("commands"), "'commands' expected: " + rootNode);
          for (UNode childNode : rootNode.getMemberList()) {
              cmdSet.addOwner(childNode);
          }
          return cmdSet;
      }
docs: Create a RESTCatalog serialized as a {@link UNode} tree. An exception is thrown if
  a parsing error occurs.
  
  @param rootNode  Root of a {@link UNode} true.
  @return          New RESTCatalog parsed from the give JSON document.