string GetHomesForBuilding(List <VerticalsCsv> verticalsCsvList) { var verticalsList = new List <Verticals>(); List <VerticalsTechnology> verticalTechnologyList; foreach (var verticalItem in verticalsCsvList.GroupBy(x => x.Gescal37)) { var verticalResponse = CastHelper.GetRespuestaVertical(verticalItem.First().Gescal37); Verticals verticalMapped = MappingBasicInfoVertical(verticalResponse); verticalTechnologyList = verticalItem.ToList().Mapper <VerticalsCsv, VerticalsTechnology>(); verticalMapped.Technologies = new List <VerticalsTechnology>(); verticalMapped.Technologies.AddRange(verticalTechnologyList); verticalsList.Add(verticalMapped); } return(JsonConvert.SerializeObject(verticalsList)); }