    @DataProvider(value = {

        "true",
        "false"
    })
    @Test
    public void pair_constructor_sets_fields_as_expected_when_pair_is_null(boolean useStaticFactory) {
        // when
        BiConsumerWithTracing instance = (useStaticFactory)
                                       ? withTracing(biConsumerMock, (Pair)null)
                                       : new BiConsumerWithTracing(biConsumerMock, (Pair)null);

        // then
        assertThat(instance.origBiConsumer).isSameAs(biConsumerMock);
        assertThat(instance.spanStackForExecution).isNull();
        assertThat(instance.mdcContextMapForExecution).isNull();
    }