private static final char PAD = '=';

    private static final byte[] DECODE_TABLE = new byte[128];
    static {
        for (int i = 0; i < DECODE_TABLE.length; i++) {
            DECODE_TABLE[i] = Byte.MAX_VALUE;
        }
        for (int i = 0; i < ENCODE_TABLE.length; i++) {
            DECODE_TABLE[ENCODE_TABLE[i]] = (byte) i;
        }
    }

    /**
     * Encodes data in Base64.
     *