@Override
    public Map<String, Metric> getMetrics() {
        return metricRegistry.getMetrics();
    }
@Test
    public void shouldReturnTotalNumberOfRequestsAs1ForSuccessVoid() {
        HelloWorldService helloWorldService = mock(HelloWorldService.class);

        Retry retry = Retry.of("metrics", RetryConfig.<String>custom()
                .retryOnResult(String::isEmpty)
                .maxAttempts(5)
                .build());


        retry.executeRunnable(helloWorldService::sayHelloWorld);

        assertThat(retry.getMetrics().getNumberOfTotalCalls()).isEqualTo(1);
    }