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

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

        // then
        assertEquals(PROJECT, result);
    }