private void _deleteRight(object obj)
        {
            var rightToDelete = SelectedRight;

            if (Rights.Remove(rightToDelete))
            {
                rightToDelete.Dispose();
                rightToDelete.Modified -= EventRightViewmodel_Modified;
                IsModified              = true;
            }
        }
        public Result <DataProcessingRegistrationRight, OperationError> RemoveRole(DataProcessingRegistrationRole role, User user)
        {
            if (role == null)
            {
                throw new ArgumentNullException(nameof(role));
            }
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            return(GetRight(role, user)
                   .Match <Result <DataProcessingRegistrationRight, OperationError> >
                   (
                       right =>
            {
                Rights.Remove(right);
                return right;
            },
                       () => new OperationError($"Role with id {role.Id} is not assigned to user with id ${user.Id}",
                                                OperationFailure.BadInput)
                   ));
        }