cognitoUser/userPool.storage.sync is not a function about react-native-aws-cognito-js HOT 4 CLOSED

export const checkIfLoggedIn = () => {
    return (dispatch) => {
        dispatch({ type: DO_NOTHING });
        var userPool = new CognitoUserPool(appConfig);
        var cognitoUser = userPool.getCurrentUser();
        console.log(cognitoUser);
        if (cognitoUser != null) {
            cognitoUser.getSession(function(err, session) {
                if (err) {
                    console.log(err);
                    return;
                }
                console.log('session validity: ' + session.isValid());

                // NOTE: getSession must be called to authenticate user before calling getUserAttributes
                cognitoUser.getUserAttributes(function(err, attributes) {
                    if (err) {
                        // Handle error
                    } else {
                        // Do something with attributes
                        console.log(attributes);
                    }
                });
                // in the future, you can insert here code to set token to access aws resources based on user access
                Actions.main({ type: 'reset' });
            });
        }
    }
};