@Test
public void exceptionInConvertFallbackedTest() {

    final ResponseBody responseBody = mock(ResponseBody.class);
    when(responseBody.source()).thenThrow(new RuntimeException());
    final LineMessagingException result =
            target.apply(Response.error(401, responseBody));
    assertThat(result)
            .isInstanceOf(GeneralLineMessagingException.class);
}