@Test
public void virtualPropertyWriterInstanceReturnsSingleton() {

    // given
    VirtualProperty[] customProperties = new VirtualProperty[0];
    Log4j2Lookup valueResolver = new Log4j2Lookup(null);
    JacksonHandlerInstantiator handlerInstantiator = createTestHandlerInstantiator(customProperties, valueResolver);
    MapperConfig config = new ObjectMapper().getSerializationConfig();
    // when
    VirtualBeanPropertyWriter result1 = handlerInstantiator.virtualPropertyWriterInstance(
            config,
            VirtualPropertiesWriter.class
    );
    VirtualBeanPropertyWriter result2 = handlerInstantiator.virtualPropertyWriterInstance(
            config,
            VirtualPropertiesWriter.class
    );
    // then
    Assert.assertTrue(result1 == result2);
}