@Test
public void Academy여러개를_EntityGraph로_가져온다() throws Exception {

    //given
    List<Academy> academies = academyRepository.findAllEntityGraph();
    List<String> subjectNames = academyService.findAllSubjectNamesByEntityGraph();
    //then
    assertThat(academies.size(), is(20));
    assertThat(subjectNames.size(), is(20));
}