How to subscribe to a Kafka topic using NestJS KafkaClient?

Question

I am implementing kafka adapter using NestJS adapters. Within this adapter, I need to be able to publish and subscribe to Kafka topics. The adapter class is not a controller, so I can't add @EventPattern() methods there. I can inject kafkaClient and be able to only send messages:

export class KafkaAdapter extends IoAdapter {
  constructor(
    private readonly app: INestApplicationContext,
    private kafkaClient: ClientKafka,
  ) {
    super(app);
  }

  createIOServer(port: number, options?: any): any {
    const server: Server = super.createIOServer(port, options);
    const client = this.kafkaClient;
    server.adapter(function (nsp) {
      // using kafkaClient to send/emit messages 
    });
    return server;
  }
}

But it seems I can't subscribe to Kafka topics with this kafkaClient. The consumer is created but not exposed to a public KafkaClient interface. So I forced to initialize another custom consumer, which is creating a separate connection to Kafka, and I don't like it.

Any way to subscribe to Kafka topics outside of controllers?