public void sendPdu(final byte[] pdu) {
        if (!mIsDeviceReady)
            return;

        // This callback will be called each time the data were sent.
        final DataSentCallback callback = (device, data) ->
                mCallbacks.onDataSent(device, getMaximumPacketSize(), data.getValue());

        // Write the right characteristic.
        final BluetoothGattCharacteristic characteristic = isProvisioningComplete ?
                mMeshProxyDataInCharacteristic : mMeshProvisioningDataInCharacteristic;
        writeCharacteristic(characteristic, pdu, BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE)
                .split()
                .with(callback)
                .enqueue();
    }
Sends the mesh pdu.
<p>
The function will chunk the pdu to fit in to the mtu size supported by the node.

@param pdu mesh pdu.
app/src/main/java/no/nordicsemi/android/nrfmesh/ble/BleMeshManager.java