public HttpResponseMessage GetRacksDisponiveis([FromUri] int salaId, int tamanho)
{
List <Slot> slots = contexto.Slots
.AsNoTracking()
.Where(x => x.Sala.Id == salaId)
.ToList();
List <int> slotsId = new List <int>();
slots.ForEach(x => slotsId.Add(x.Id));
List <Rack> racks = contexto.Racks
.AsNoTracking()
.Where(x => slotsId.Contains(x.Slot.Id))
.ToList();
return(Ok(racks.Where(x => ControllerUtils.RackIsDisponivel(contexto, x.Id, tamanho))));
}