public void verifyPassword(AttendeePassword other) {
        if (!this.equals(other)) {
            throw new MomoException(AttendeeErrorCode.PASSWORD_MISMATCHED);
        }
    }
@DisplayName("비밀번호가 서로 다르면 예외를 발생시킨다.")
    @Test
    void throwsExceptionForMismatchedPasswords() {
        AttendeePassword password = new AttendeePassword("1234");
        AttendeePassword other = new AttendeePassword("123456");

        assertThatThrownBy(() -> password.verifyPassword(other))
                .isInstanceOf(MomoException.class)
                .hasMessage(AttendeeErrorCode.PASSWORD_MISMATCHED.message());
    }