List<String> zones(String project, String region, String accessToken) {
        String url = String.format("%s/compute/v1/projects/%s/regions/%s?alt=json&fields=zones", endpoint, project, region);
        String response = RestClient
                .create(url)
                .withHeader("Authorization", String.format("OAuth %s", accessToken))
                .get()
                .getBody();

        JsonArray zoneUrls = toJsonArray(Json.parse(response).asObject().get("zones"));

        List<String> zones = new ArrayList<>();
        for (JsonValue value : zoneUrls) {
            zones.add(lastPartOf(value.asString(), "/"));
        }
        return zones;
    }
@Test
    public void zones() {
        // given
        stubFor(get(urlEqualTo(
                String.format("/compute/v1/projects/%s/regions/%s?alt=json&fields=zones", PROJECT, REGION)))
                .withHeader("Authorization", equalTo(String.format("OAuth %s", ACCESS_TOKEN)))
                .willReturn(aResponse().withStatus(HttpURLConnection.HTTP_OK).withBody(regionResponse(PROJECT, REGION))));
        // when
        List<String> zones = gcpComputeApi.zones(PROJECT, REGION, ACCESS_TOKEN);

        // then
        String zoneA = REGION + "-a";
        String zoneB = REGION + "-b";
        String zoneC = REGION + "-c";
        assertEquals(asList(zoneA, zoneB, zoneC), zones);
    }