code: function partNode(node){
        if (node.isPart && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
          node.currentText = node.firstChild.nodeValue;
          return !/[\n\t\r]/.test(node.currentText);
        }
        return false;
      }
docs: Check whether a node is a normalized <span> element.