public static String convertChecksumToString(int checksum) {
        ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES);
        buffer.order(ByteOrder.BIG_ENDIAN);
        buffer.putInt(checksum);
        return BASE64_ENCODER.encodeToString(buffer.array());
    }
@Test
    public void shouldConvertToStringChecksum() {
        assertEquals("AAAwOQ==", ChecksumUtils.convertChecksumToString(12345));
        assertEquals("AADUMQ==", ChecksumUtils.convertChecksumToString(54321));
    }