default KeyValueIterator<K, V> reverseAll() {
        throw new UnsupportedOperationException();
    }
Return a reverse iterator over all keys in this store. This iterator must be closed after use.
The returned iterator must be safe from {@link java.util.ConcurrentModificationException}s
and must not return null values.
Order is not guaranteed as bytes lexicographical ordering might not represent key order.

@return A reverse iterator of all key/value pairs in the store, from largest to smallest key bytes.
@throws InvalidStateStoreException if the store is not initialized
streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyKeyValueStore.java