class ByteUtilities {

    static byte[] concat(byte[] b1, byte[] b2, int b2Length)
    {
        byte[] concat = new byte[b1.length + b2Length];
        System.arraycopy(b1, 0, concat, 0, b1.length);
        System.arraycopy(b2, 0, concat, b1.length, b2Length);
        return concat;
    }

    private  ByteUtilities();

}