qQp5AuGY

1    public static <R, T> Func1<T, Observable<R>> memoizeAndCache(Func1<T, Observable<R>> builder) {
2        Map<T, Observable<R>> map = new HashMap<>();
3        return r -> map.computeIfAbsent(r, r2 -> builder.call(r2).cache());
4    }
5
6    private Observable<OauthToken> getValidTokenToContext(Map<Parameter, Object> context) {
7        OauthToken token = (OauthToken) context.get(Parameter.TOKEN);
8        if (isValidToken(Optional.ofNullable(token))) {
9            return Observable.just(token);
10        }
11        Func1<Map<Parameter, Object>, Observable<OauthToken>> cache = memoizeAndCache(this::getToken);
12        return cache.call(context)
13                .doOnNext(t -> context.put(Parameter.TOKEN, t));