@Test
public void returnedObjectMapperIsACopyOfInternalMapper() {

    // given
    ObjectMapper configuredObjectMapper = new ObjectMapper();
    FailedItemMarshaller failedItemMarshaller = new FailedItemMarshaller() {
        @Override
        ObjectMapper createConfiguredObjectMapper() {
            return configuredObjectMapper;
        }
    };
    // when
    ObjectMapper result = failedItemMarshaller.objectMapper();
    // then
    assertNotSame(configuredObjectMapper, result);
}