public IEnumerable <Bird> GetBirds(Enums.UnitOfMeasurement unitOfMeasurement = Enums.UnitOfMeasurement.Milliarchieops) { var birdsData = _birdRepository.GetBirds(); var birdsModel = birdsData.Select(BirdDto.FromBirdDataToBirdModel); double umTimes = _unitOfMeasurementService.ConvertUnit(unitOfMeasurement); List <Bird> list = new List <Bird>(); var birds = birdsModel as IList <Bird> ?? birdsModel.ToList(); foreach (var bird in birds) { list.Add(bird); } list.ForEach(b => { b.Height = Math.Round(b.Height * umTimes, 2); b.Length = Math.Round(b.Length * umTimes, 2); b.Girth = Math.Round(b.Girth * umTimes, 2); }); return(birds); }