public boolean flushedEntryRemoved(final K key) {
        return flushedRemovals.contains(key);
    }
Determine whether the store {@link KeyValueStore#flush() flushed} the removal of the given key.

@param key the key
@return {@code true} if the entry with the given key was removed when flushed, or {@code false} if the entry was not
removed when last flushed
streams/src/test/java/org/apache/kafka/streams/state/KeyValueStoreTestDriver.java