How to add basic auth to Autowired testRestTemplate in SpringBootTest; Spring Boot 1.4

This got fixed in Spring Boot 1.4.1 which has an additional method

testRestTemplate.withBasicAuth(USERNAME,PASSWORD)

@Autowired
private TestRestTemplate testRestTemplate;

@Test
public void testOAuthAccessTokenIsReturned() {
    MultiValueMap<String, String> request = new LinkedMultiValueMap<String, String>();
    request.set("username", USERNAME);
    request.set("password", password);
    request.set("grant_type", "password");
    @SuppressWarnings("unchecked")
    Map<String, Object> token = this.testRestTemplate.withBasicAuth(CLIENT_NAME, CLIENT_PASSWORD)
            .postForObject(SyntheticsConstants.OAUTH_ENDPOINT, request, Map.class);
    assertNotNull("Wrong response: " + token, token.get("access_token"));
}