@Test
@PrepareForTest({ HttpUtils.class, IOUtils.class })

public void executeHttpGetRequestTestErrorCode() throws Exception {
    HttpURLConnection httpConn = configureExecuteHttpGetRequestTest(url, 400);
    String result = spy.executeHttpGetRequest(url);
    verifyExecuteHttpGetRequestTest(httpConn, 0);
    Assert.assertEquals(String.format("Error in HTTP GET : code [%d]", 400), result);
}