String currentZone() {
        String urlString = String.format("%s/computeMetadata/v1/instance/zone", endpoint);
        String zoneResponse = callGet(urlString);
        return lastPartOf(zoneResponse, "/");
    }
@Test
    public void currentZone() {
        // given
        stubFor(get(urlEqualTo("/computeMetadata/v1/instance/zone"))
                .withHeader("Metadata-Flavor", equalTo("Google"))
                .willReturn(aResponse().withStatus(HttpURLConnection.HTTP_OK).withBody(zoneResponse(ZONE))));

        // when
        String result = gcpMetadataApi.currentZone();

        // then
        assertEquals(ZONE, result);
    }