Emitter

Single.fromEmitter(new Action1<SingleEmitter<KKMStatus>>() {
            @Override
            public void call(final SingleEmitter<KKMStatus> emitter) {
                kkMv2.getStatus(new KKMCallbackWithResult<KKMStatus>() {
                    @Override
                    public void onSuccess(KKMStatus result) {
                        emitter.onSuccess(result);
                    }

                    @Override
                    public void onError(String reason) {
                        emitter.onError(new Throwable(reason));
                    }
                });
            }
        });