CachedFilterData

          .Instance()   // my own cache object

          .GetSalesVolumeKeys(filterExpression)  // method returns list of records fulfilling the filter expression

          .Select(b => b.Qsv.Name) // pick out the name in each record, return a list of names 

          .Distinct()   // remove duplicates

          .ForEach( // for each of those names

            qsvName => resultlist.Add(

                     new QsvsForFilter()

                     {

                       FilterId=namedFilter.Id,

                       FromPeriod = model.FromPeriod,

                       ToPeriod = model.ToPeriod,

                       CreatedAt = now,

                       CreatedBy = Current.Username,

                       Qsv = qsvName

                     }));