code: public final B eventLoop(EventLoop eventLoop) {
          requireNonNull(eventLoop, "eventLoop");
          checkArgument(TransportType.isSupported(eventLoop),
                        "unsupported event loop type: %s", eventLoop);
  
          this.eventLoop = eventLoop;
          return self();
      }
docs: Sets the {@link EventLoop} to use for sending DNS queries.