public boolean matches(String groupAccessCode) {
        return code.equals(Encoder.encode(groupAccessCode));
    }
@Test
    void 코드_일치_여부를_판단한다() {
        // given
        String code = "hello";
        GroupAccessCode groupAccessCode = new GroupAccessCode(code);

        // when, then
        assertThat(groupAccessCode.matches("hello")).isTrue();
    }