private static byte[] createPrivacyRandom(@NonNull final byte[] encryptedUpperTransportPDU) {
        final byte[] privacyRandom = new byte[7];
        System.arraycopy(encryptedUpperTransportPDU, 0, privacyRandom, 0, privacyRandom.length);
        return privacyRandom;
    }
Creates the privacy random.

@param encryptedUpperTransportPDU Encrypted transport pdu
@return Privacy random
mesh/src/main/java/no/nordicsemi/android/mesh/transport/NetworkLayer.java