let RetryStrategy = attempts => attempts
    .zip(Observable.range(1, 4))
    .flatMap(([error, i]) => {
        if (i > 3) {
            return Observable.throw('Network error occured')
        }
        return Observable.timer(i * 1000)
    })

export const deleteSurveyQuestionEpic = (action$, {getState, dispatch}) =>
    action$.ofType('MY_ACTION')
        .switchMap(
            action => ajax.delete(`myURL`)
                .map(res => res.response)
                .flatMap(response => {
                    console.log(response) // <-- returns null
                    return arrayRemove('formName', 'questions', 1) // <-- redux-form action-creator
                })
                .retryWhen(RetryStrategy)
                .takeUntil(action$.ofType('MY_CANCEL_ACTION'))
                .catch((e) => {
                    return Observable.of(
                        errorSurvey((e.xhr && `Error ${e.xhr.statusText}: ${e.xhr.statusText}`) || 'Network error occured')
                    )
                })
        )