public Map<String, KafkaFuture<Void>> values() {
        return futures.entrySet().stream()
                .collect(Collectors.toMap(Map.Entry::getKey, e -> e.getValue().thenApply(v -> null)));
    }
Return a map from topic names to futures, which can be used to check the status of individual
topic creations.
clients/src/main/java/org/apache/kafka/clients/admin/CreateTopicsResult.java