code: function(callback){
          callback = callback || function(){};
          var res = [], _this = this, obj = null, callbackReturn;
          this._dataCache.forEach(function(item){
              if(item.type == 'group'){
                  res.push({
                      type : item.type,
                      value : _this._map(item.value, callback),
                      parent : item.parent,
                      name : item.name
                  });
              }else{
                  obj = clone(item);
                  callbackReturn = callback.call(obj, obj, item);
                  if(callbackReturn != false){
                      res.push(obj);
                  }
                  obj = null;
              }
          });
          res = new HostAdmin()._loadJSON(res);
          return res;
      }
docs: 复制
  @param callback {Function}
  @return {Array}