class JsonRestClientImpl implements JsonRestClient {

  @Override
  public JsonNode get(final String url, final RestRequestHeader... requestHeaders) throws JsonProcessingException, IOException {
    final ResponseEntity<String> response = restClient.get(url, String.class, requestHeaders);
    return getJson(response);
  }

}

class JsonRestClientImplTest  {

  private static final String ANY_URL;
  private static final String RESPONSE_STUB_PATH;
  @InjectMocks
  private JsonRestClient jsonRestClient;
  private String responseStub;

  @Test
  public void testGet() throws JsonProcessingException, IOException {

    setupExpectation(HttpMethod.GET);
    assertResponseOk(jsonRestClient.get(ANY_URL));
  }

}