Group By 여러 조건 사용하기

https://stackoverflow.com/questions/6935264/group-by-with-multiple-columns-using-lambda

IEnumerable<IEnumerable<PlanItem>> groupList = exchangeList.GroupBy(g => new { g.VVD, g.POL, g.POD, g.CargoID, g.CrgID, g.Weight });