@SuppressWarnings("unchecked")
            @Override
            public <R> QueryResult<R> query(final Query<R> query, final PositionBound positionBound, final QueryConfig config) {
                if (query instanceof TestQuery) {
                    return (QueryResult<R>) QueryResult.forResult("success");
                } else {
                    throw new UnsupportedOperationException();
                }
            }
Custom {@link VersionedKeyValueStore} implementation solely for the purpose of testing
IQv2 queries. All other methods are unsupported / no-ops.
streams/src/test/java/org/apache/kafka/streams/integration/VersionedKeyValueStoreIntegrationTest.java