docs: function(o,start,end){
         var i = 0,len = o.length;
         if(!len || len <= 0) return false;
         start = Math.abs(start); end = Math.abs(end);
         if(end > (len - start)){
          end = (len - start);
        }
  
        for(; i < len; i++){
          o[i] = o[start];
          start +=1;
          if(i >= end) break;
        }
  
        o.length = end;
        return o;
  
      }