@Override
protected void internalInit() {
super.internalInit();
CommonHelper.assertNotBlank("fields", this.fields);
this.api20 = new ExtendedFacebookApi();
if (StringUtils.isNotBlank(this.scope)) {
this.service = new StateOAuth20ServiceImpl(this.api20, new OAuthConfig(this.key, this.secret,
this.callbackUrl,
SignatureType.Header, this.scope,
null), this.connectTimeout,