default WindowStoreIterator<V> backwardFetch(K key, Instant timeFrom, Instant timeTo) throws IllegalArgumentException  {
        throw new UnsupportedOperationException();
    }
Get all the key-value pairs with the given key and the time range from all the existing windows
in backward order with respect to time (from end to beginning of time).
<p>
This iterator must be closed after use.
<p>
The time range is inclusive and applies to the starting timestamp of the window.
For example, if we have the following windows:
<pre>
+-------------------------------+
|  key  | start time | end time |
+-------+------------+----------+
|   A   |     10     |    20    |
+-------+------------+----------+
|   A   |     15     |    25    |
+-------+------------+----------+
|   A   |     20     |    30    |
+-------+------------+----------+
|   A   |     25     |    35    |
+--------------------------------
</pre>
And we call {@code store.backwardFetch("A", Instant.ofEpochMilli(10), Instant.ofEpochMilli(20))} then the
results will contain the first three windows from the table above in backward order,
i.e., all those where 10 &lt;= start time &lt;= 20.
<p>
For each key, the iterator guarantees ordering of windows, starting from the newest/latest
available window to the oldest/earliest window.

@param key  the key to fetch
@param timeFrom time range start (inclusive), where iteration ends.
@param timeTo   time range end (inclusive), where iteration starts.
@return an iterator over key-value pairs {@code <timestamp, value>}, from end to beginning of time.
@throws InvalidStateStoreException if the store is not initialized
@throws NullPointerException       if {@code null} is used for key.
@throws IllegalArgumentException   if duration is negative or can't be represented as {@code long milliseconds}
streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyWindowStore.java