You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: command_mq_topic_list.go
    path of file: ./repos/seaweedfs/weed/shell
    
    the code of the file until where you have to start completion: package shell

import (
	"context"
	"fmt"
	"github.com/seaweedfs/seaweedfs/weed/mq/pub_balancer"
	"github.com/seaweedfs/seaweedfs/weed/pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
	"io"
)

func init() {
	Commands = append(Commands, &commandMqTopicLi
    
func findBrokerBalancer(commandEnv *CommandEnv) (brokerBalancer string, err error) {
	err = commandEnv.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
		resp, err := client.FindLockOwner(context.Background(), &filer_pb.FindLockOwnerRequest{
			Name: pub_balancer.LockBrokerBalancer,
		})
		if err != nil {
			return err
		}
		brokerBalancer = resp.Owner
		return nil
	})
	return
}