@Test
  public void test_이메일이_비어있습니다() {

    SignupUser signupMember = new SignupUser();
    signupMember.setPassword("test");
    signupMember.setReTypePassword("test");

    Set<ConstraintViolation<SignupUser>> constraintViolations = validator.validate(signupMember);

    log.debug(constraintViolations.toString());

    assertEquals(1, constraintViolations.size());
  }