@SuppressLint("MissingPermission") // We check before this is called
    public void setCharacteristicNotification(final BluetoothGattCharacteristic characteristic, final boolean enabled) {
        if (mBluetoothAdapter == null || mBluetoothGatt == null) {
            Log.w(TAG, "BluetoothAdapter not initialized");
            return;
        }
        mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
    }
Enables or disables notification on a give characteristic.

@param characteristic Characteristic to act on.
@param enabled        If true, enable notification.  False otherwise.
sample_app/src/main/java/uk/co/alt236/btlescan/services/BluetoothLeService.java