How to mock private methods using PowerMockito?

Question

I want to mock private method newHttpClient(), but while execution this method is actually being called.

I have seen several problems on same query as mine and tried the suggestions but it's not working.

Class code -

class MyService {

    private CloseableHttpClient newHttpClient() {

        try {
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
                    new SSLContextBuilder().loadTrustMaterial(TrustAllStrategy.INSTANCE).build(),
                    NoopHostnameVerifier.INSTANCE);
            logger.info("Inside new http client");
            return HttpClients.custom().setSSLSocketFactory(sslsf).build();
        } catch (KeyManagementException | NoSuchAlgorithmException | KeyStoreException exception) {
            logger.error(exception);
        }

        return null;
    }

    public String create(CreateRequestDTO Request) {

        CloseableHttpClient client = newHttpClient();
        CloseableHttpResponse response = null;

        HttpPut httpPut = new HttpPut("MyUrl...");

        try {
            response = client.execute(httpPut);
        } catch (IOException exception) {
            return "exception";
        }
        return response.toString();
    }
}

Test class code -

@PrepareForTest({ MyService.class })
@PowerMockIgnore({ "com.sun.org.apache.xerces.*", "javax.xml.*", "org.xml.*", "org.w3c.*", "com.sun.org.apache.xalan.*",
        "javax.activation.*", "javax.management.*", "javax.net.ssl.*", "javax.crypto.*" })
@RunWith(PowerMockRunner.class)
public class MyServiceTest {

    @InjectMocks
    private MyService MyService;

    @Mock
    private CloseableHttpClient closeableHttpClient;

    @Mock
    private HttpClient httpClient;

    @Mock
    private CloseableHttpResponse closeableHttpResponse;

    @Mock
    private HttpPut httpPut;

    @Mock
    private HttpEntity httpEntity;

    @Before
    public void setupTest() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void testCreate() throws Exception {
        // MyService MyServiceSpy = PowerMockito.mock(MyService);
        MyService MyServiceSpy = PowerMockito.spy(MyService);
        CreateRequestDTO createRequestDTO = new CreateRequestDTO();
        createRequestDTO.setLocation("room 1");
        createRequestDTO.setStartTime("3 pm");
        createRequestDTO.setEndTime("4 pm");

        try {

            PowerMockito.doReturn(closeableHttpClient).when(MyServiceSpy, "newHttpClient");

            // PowerMockito.when(MyServiceSpy,
            // "newHttpClient").thenReturn(httpClient);

            // PowerMockito.verifyPrivate(MyServiceSpy).invoke("newHttpClient");

            String jsonEntity = " created successfully";

            HttpEntity httpEntity = EntityBuilder.create().setText(jsonEntity)
                    .setContentType(org.apache.http.entity.ContentType.APPLICATION_JSON).build();

            closeableHttpResponse.setEntity(httpEntity);

            PowerMockito.doReturn(closeableHttpResponse).when(closeableHttpClient).execute(any(HttpPut.class));

            String res = MyService.create(createRequestDTO);
            logger.info("Result from create : " + res);
            Assert.assertTrue(res.substring(0, 5).matches("BEGIN"));

        } catch (Exception e) {
            e.printStackTrace();
            throw e;
        }
    }

}

On execution "Inside new http client" is logged, but it shouldn't.