WeiboJsonExtractorTest - Refactored

@Test
public void createTokenHasUid() throws IOException {
    OAuth2AccessToken accessToken = extractor.createToken("ACCESS_TOKEN", null,
        123, null, null, mapper.readTree(responseOk), responseOk);

    Assert.assertEquals("ACCESS_TOKEN", accessToken.getAccessToken());

    assertTrue(accessToken instanceof WeiboToken);

    Assert.assertEquals("12341234", ((WeiboToken) accessToken).getUid());
}