for (int i = 0; i < size; i++) {
            data[i] = (byte) (i % 256);
        }
        return data;
    }

    /**
     * Create a test string with specified length
     */
    protected String createTestString(int length) {
        StringBuilder sb = new StringBuilder(length);
        for (int i = 0; i < length; i++) {
            sb.append((char) ('A' + (i % 26)));
        }
        return sb.toString();
    }