docs: function addValue(e){
  
      var len;
  
      if (e.old === 'valueStart') {
        var history = this.get('history');
        len = history.length;
        var preStatus = history[len - 3];
        isNew = preStatus == 'ruleStart';
        value = this._getLast(isNew, 'values');
  
        value && value.push(e.data);
      } else {
        var metas = this.get('metas');
        var selectors = this.get('selectors');
        len = selectors.length;
        metas[len] = metas[len] || [];
        var data = '';
  
        /*when @import url("booya.css") print, screen;*/
        if (e.old === 'selectorBreak'){
          data = selectors.pop().join(', ') + ', ';
          var lines = this.get('lines');
          lines.pop();
        }
  
        data += e.data;
        metas[len].push(data);
      }
    }