@Test
public void loadRegistry() {

    final MappingContext fooCtx = MappingContexts.mock(true);
    final MessageMapperRegistry underTest = this.underTest.registryOf(DittoMessageMapper.CONTEXT,
            ConnectivityModelFactory.newPayloadMappingDefinition("foo", fooCtx));
    final MessageMapper fooMapper = underTest.getMappers(ConnectivityModelFactory.newPayloadMapping("foo")).get(0);
    final MessageMapper defaultMapper = underTest.getDefaultMapper();
    assertThat(fooMapper).isInstanceOf(WrappingMessageMapper.class);
    assertThat(((WrappingMessageMapper) fooMapper).getDelegate()).isInstanceOf(MockMapper.class);
    assertThat(defaultMapper).isInstanceOf(WrappingMessageMapper.class);
    assertThat(((WrappingMessageMapper) defaultMapper).getDelegate()).isInstanceOf(DittoMessageMapper.class);
}