public Client getClient(int? id)
        {
            var c = dc.Clients.Include("Banks").FirstOrDefault(i => i.Id == id);

            if (c != null)
            {
                Client vc = new Client();
            
                vc.Id = c.Id;
                vc.FirstName = c.FirstName;
                vc.LastName = c.LastName;
                vc.AccountNumber = c.AccountNumber;

                var lbs = new List<Bank>();
                foreach (var item in c.Banks)
                {
                    Bank b = new Bank();
                    b.Id = item.Id;
                    b.Name = item.Name;
                    b.Code = item.Code;
                    lbs.Add(b);
                }
                vc.Banks = lbs;
                return vc;
            }

            return null;
        }
        public List<Client> getListOfClients()
        {
            var cs = dc.Clients.OrderBy(n => n.Id);

            List<Client> lcs = new List<Client>();

            foreach (var item in cs)
            {
                Client cn = new Client();
                cn.Id = item.Id;
                cn.FirstName = item.FirstName;
                cn.LastName = item.LastName;
                cn.AccountNumber = item.AccountNumber;
                lcs.Add(cn);
            }

            return lcs;
        }
        public Client createClient(ClientCreateForHttpPost cp)
        {
            var c = new Client();

            c.Id = dc.Clients.Max(n => n.Id) + 1;
            c.FirstName = cp.FirstName;
            c.LastName = cp.LastName;
            c.AccountNumber = cp.AccountNumber;

            c.Banks = new List<Bank>();
            foreach (var item in cp.BankIds)
            {
                Bank b = dc.Banks.FirstOrDefault(bk => bk.Id == item);
                if (b != null) c.Banks.Add(b);
            }
            dc.Clients.Add(c);
            dc.SaveChanges();

            return getClient(c.Id);
        }