@Test
public void loadMapperFromFactoryMethod() {

    final Map<String, String> options = new HashMap<>();
    // add this to pass configuration checks
    options.put(MockMapper.OPT_IS_VALID, String.valueOf(true));
    // looking for a method containing 'test' and returning a MessageMapper in Mappers.class
    final MappingContext ctx = MappingContexts.mock("test", options);
    assertThat(underTest.mapperOf("test", ctx)).isPresent();
}