@Test
  public void 테스트_getStackTraceString() {
    Exception e = new InvalidClassException("e");

    assertThat(ExceptionUtil.createStacktrace(null)).isNull();
    assertThat(ExceptionUtil.createStacktrace(e)).isNotNull();
  }
  @Test
  public void 테스트_getExceptionType() {
    Exception e = new IllegalArgumentException("e");

    assertThat(ExceptionUtil.createExceptionType(null)).isNull();
    assertThat(ExceptionUtil.createExceptionType(e)).isNotNull();
  }