List<int> list = new List<int>();
 foreach (var item in collection)
            {
              PepareData preData = new PepareData(item);
               preData.RunActions();
            list.AddRange(preData.ListResultData)
            }

  PepareData preData = new PepareData();
 foreach (var item in collection)
            {
                preData.LoadData(item);
                preData.RunActions();
            }