static <T> Supplier<T> decorateSupplier(Observation observation, Supplier<T> supplier) {
        return () -> observation.observe(supplier);
    }
@Test
    public void shouldDecorateSupplier() throws Throwable {
        given(helloWorldService.returnHelloWorld()).willReturn("Hello world");
        Supplier<String> timedSupplier = Observations
            .decorateSupplier(observation, helloWorldService::returnHelloWorld);

        timedSupplier.get();

        assertThatObservationWasStartedAndFinishedWithoutErrors();
        then(helloWorldService).should().returnHelloWorld();
    }