public User Register(RegisterUserCommand command)
        {
            var tenant = new Tenant(command.FullName, string.Empty);
            var user = tenant.RegisterTenantUser(command.UserName, command.Password, command.Email);

            if (tenant.IsValid(user))
            {
                _tenantRepository.Register(tenant, user);
                DomainEvents.Raise(new UserRegistered(user));
                return user;
            }

            return null;
        }
 public void Register(Tenant tenant, User user)
 {
     _dataContext.Tenants.Add(tenant);
     _dataContext.Users.Add(user);
     _dataContext.SaveChanges();
 }