adjust `test_reset_email_user_deleted` for `None` instead of str

        self.user_manager.delete(user)

        assert user.deleted is True

        message = self.user_manager.send_reset_email(self.trans, {"email": user_email})

        assert message == "Failed to produce password reset token. User not found."

        assert message == None

    def test_get_user_by_identity(self):

        # return None if username/email not found