public void Remove(UserModel user)
 {
     Should.NotBeNull(user, "user");
     _users.Remove(user);
 }
 private void InitializeNewUser()
 {
     var userModel = new UserModel();
     UserEditorViewModel.InitializeEntity(userModel, true);
     //NOTE: to show how you can manually add validator
     UserEditorViewModel.AddValidator<UserEmailValidator>(userModel);
 }
 public void Add(UserModel user)
 {
     Should.NotBeNull(user, "user");
     _users.Add(user);
 }