public boolean addCharacteristic(BluetoothGattCharacteristic characteristic) {
        mCharacteristics.add(characteristic);
        characteristic.setService(this);
        return true;
    }
Used for mocks and constants in rxandroidble, but instances created in mockrxandroidble, so the methods must be implemented
rxandroidble/src/test/java/android/bluetooth/BluetoothGattService.java