private byte[] getAdvertisedNetworkId(final byte[] serviceData) {
        if (serviceData == null)
            return null;
        final ByteBuffer advertisedNetworkID = ByteBuffer.allocate(ADVERTISED_NETWORK_ID_LENGTH).order(ByteOrder.BIG_ENDIAN);
        advertisedNetworkID.put(serviceData, ADVERTISED_NETWORK_ID_OFFSET, ADVERTISED_HASH_LENGTH);
        return advertisedNetworkID.array();
    }
Returns the advertised network identity

@param serviceData advertised service data
@return returns the advertised network identity
mesh/src/main/java/no/nordicsemi/android/mesh/MeshManagerApi.java