presto-kafka/src/main/java/io/prestosql/plugin/kafka/KafkaSimpleConsumerManager.java/KafkaSimpleConsumerManager/getConsumer
class KafkaSimpleConsumerManager:    public SimpleConsumer getConsumer(HostAddress host)
    {
        requireNonNull(host, "host is null");
        return consumerCache.getUnchecked(host);
    }