private synchronized byte[] get(final Bytes key, final Optional<Snapshot> snapshot) {
        if (snapshot.isPresent()) {
            try (ReadOptions readOptions = new ReadOptions()) {
                readOptions.setSnapshot(snapshot.get());
                return physicalStore.get(prefixKeyFormatter.addPrefix(key), readOptions);
            }
        } else {
            return physicalStore.get(prefixKeyFormatter.addPrefix(key));
        }
    }
This "logical segment" is a segment which shares its underlying physical store with other
logical segments. Each segment uses a unique, fixed-length key prefix derived from the
segment ID when writing to the shared physical store. In other words, a logical segment
stores a key into a shared physical store by prepending the key with a prefix (unique to
the specific logical segment), and storing the combined key into the physical store.
streams/src/main/java/org/apache/kafka/streams/state/internals/LogicalKeyValueSegment.java