public void checkIsDuplicateName(List<String> names) {
        Set<String> namesSet = new HashSet<>(names);
        if (namesSet.size() < names.size()) {
            throw new SectionNameDuplicateException();
        }
    }
@Test
    void 요청에_중복된_이름이_있다면_에러를_반환한다() {
        // given
        List<String> names = List.of("Section1", "Section1", "Section2");

        // when
        // then
        assertThrows(
                SectionNameDuplicateException.class,
                () -> createSectionService.checkIsDuplicateName(names));
    }