code: public ListenableFuture<List<String>> consumeStrings(String topic, int numMessagesToConsume) {
          KafkaConsumer<String, String> consumer = createStringConsumer();
          ListenableFuture<List<ConsumerRecord<String, String>>> records = consume(topic, consumer, numMessagesToConsume);
          return Futures.transform(records, this::extractValues, MoreExecutors.directExecutor());
      }
docs: Consume specified number of string messages
  
  @param topic                Topic to consume from
  @param numMessagesToConsume Number of messages to consume
  @return ListenableFuture