public static Change<byte[]> decomposeLegacyFormattedArrayIntoChangeArrays(final byte[] data) {
        if (data == null) {
            return null;
        }
        final ByteBuffer buffer = ByteBuffer.wrap(data);
        final byte[] oldBytes = getNullableSizePrefixedArray(buffer);
        final byte[] newBytes = getNullableSizePrefixedArray(buffer);
        return new Change<>(newBytes, oldBytes);
    }
We used to serialize a Change into a single byte[]. Now, we don't anymore, but we still
need to be able to read it (so that we can load the state store from previously-written changelog records).
streams/src/main/java/org/apache/kafka/streams/kstream/internals/FullChangeSerde.java