code: public Properties producerConfig() {
          Properties props = new Properties();
          props.put("bootstrap.servers", LOCALHOST + ":" + kafkaPort);
          props.put("acks", "1");
          props.put("batch.size", "10");
          props.put("client.id", "kafka-junit");
          props.put("request.timeout.ms", "500");
  
          return props;
      }
docs: Create a minimal producer configuration that can be used to produce to this broker
  
  @return Properties