docs: function(offset){
      offset = parseInt(offset, 10) || 0;
  
      if (!this.left_)
        this.left_ = {};
  
      var value = this.left_[offset];
      if (!value)
      {
        var start = this.offset;
        var end = start + this.limit;
  
        if (this.orderDesc)
        {
          start = this.index_.length - end;
          end = start + this.limit;
        }
  
        var item = this.index_[this.orderDesc ? end + offset - 1 : start - offset];
        value = this.left_[offset] = new Value({
          value: item ? item.object : null
        });
      }
  
      return value;
    }