default KeyValueIterator<Windowed<K>, V> backwardFetch(final K keyFrom,
                                                           final K keyTo,
                                                           final long timeFrom,
                                                           final long timeTo) {
        throw new UnsupportedOperationException();
    }
Get all the key-value pairs in the given key range and time range from all the existing windows.
<p>
This iterator must be closed after use.

@param keyFrom     the first key in the range
                   A null value indicates a starting position from the first element in the store.
@param keyTo       the last key in the range
                   A null value indicates that the range ends with the last element in the store.
@param timeFrom time range start (inclusive)
@param timeTo   time range end (inclusive)
@return an iterator over windowed key-value pairs {@code <Windowed<K>, value>}
@throws InvalidStateStoreException if the store is not initialized
streams/src/main/java/org/apache/kafka/streams/state/WindowStore.java