private static Single<Pair<RxBleConnection, BluetoothGattCharacteristic>> pairWithCharacteristic(UUID characteristicUuid,
                                                                                                     RxBleConnection rxBleConnection) {
        return getCharacteristic(characteristicUuid, rxBleConnection)
                .map(bluetoothGattCharacteristic -> Pair.create(rxBleConnection, bluetoothGattCharacteristic));
    }
Presenter class for {@link AdvancedCharacteristicOperationExampleActivity}. Prepares the logic for the activity using passed
{@link Observable}s. Contains only static methods to show a purely reactive (stateless) approach.
<p>
The contract of the class is that it subscribes to the passed Observables only if a specific functionality is possible to use.
sample/src/main/java/com/polidea/rxandroidble2/sample/example4_characteristic/advanced/Presenter.java