static void Main(string[] args)
{
var visitId = VisitId.New();
var agg = new Visit(DoctorId.New(), DateTime.Now);
var rep = new VisitRepository();
var exists = rep.Get(new VisitId(Guid.Parse("b1e81cb1-0683-473a-94b6-666d9c1babe8")));
rep.Save(agg, visitId);
var vis = rep.Get(visitId);
vis.ReserveVisit(PatientId.New());
rep.Save(vis, visitId);
Console.WriteLine("Hello World!");
}