@Override
                    public ObservableSource<? extends Observable<byte[]>> apply(Boolean notUsed) {
                        if (!characteristicNotificationSources.containsKey(characteristicUuid)) {
                            return Observable.error(new IllegalStateException("Lack of notification source for given characteristic"));
                        }
                        return Observable.just(characteristicNotificationSources.get(characteristicUuid));
                    }
Value used to disable notifications or indicatinos
mockrxandroidble/src/main/java/com/polidea/rxandroidble2/mockrxandroidble/RxBleConnectionMock.java