code: function() {
        var data = this.parsed;
        var piece = data[data.length - 1],
          len = piece.length;
        return piece[len - 1] || (piece[len - 1] = {
          tag: "*"
        });
      }
docs: 获得当前解析位置所在的datum，你只需要在这个datum中塞数据即可