code: function _onSetChildNodes(event, res) {
          // res = {parentId, nodes}
          var node = nodeWithId(res.parentId);
          node.setChildrenPayload(res.nodes);
          if (_pendingRequests > 0 && --_pendingRequests === 0) {
              _onFinishedLoadingDOM();
          }
      }
docs: WebInspector Event: DOM.setChildNodes