public void Update(Client client)
        {
            var oldClient = Client.Clients.FirstOrDefault(n => n.Id == client.Id);

            if (oldClient == null)
            {
                throw new Exception("Client doesn't exist");
            }

            oldClient.Email = client.Email;
            oldClient.Name = client.Name;
        }
 public Client Save(Client client)
 {
     client.Id = Guid.NewGuid();
     Client.Clients.Add(client);
     return client;
 }
 public void Remove(Client client)
 {
     Client.Clients.Remove(client);
 }