code: function renderNode(nodeName, node) {
      var s = '';
      // if it has child it would be a ul
      if (node._hasChild) {
          for (var name in node) {
              if (!node.hasOwnProperty(name) || name === 'level' || name === '_hasChild') {
                  continue;
              }
              if(nodeName){
                  s += '<li>' + renderNode(name, node[name]) + '</li>\n';
              }else{
                  s += renderNode(name, node[name]);
              }
          }
          // because renderNode('', tocObject);
          if(nodeName){
              s = '<a href="#' + nodeName + '">' + nodeName + '</a>\n' + '<ul>\n' + s + '</ul>\n';
          }else{
              // this is the dummy nodeName, so it's the top level
              s = '' + s;
          }
      } else {
          s = '<a href="#' + nodeName + '">' + nodeName + '</a>';
      }
      return s;
  }
docs: TODO: add href