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: worker_test.go
    path of file: ./repos/juju/worker/dbaccessor
    
    the code of the file until where you have to start completion: // Copyright 2022 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.

package dbaccessor

import (
	"context"
	"errors"
	"time"

	jc "github.com/juju/testing/checkers"
	"github.com/juju/worke
    
func (s *workerSuite) TestWorkerStartupAsBootstrapNodeThenReconfigureWithLoopbackPreferredAndNotLoopbackBound(c *gc.C) {
	defer s.setupMocks(c).Finish()

	s.expectAnyLogs()
	s.expectClock()
	s.expectTrackedDBKill()

	dataDir := c.MkDir()
	mgrExp := s.nodeManager.EXPECT()
	mgrExp.EnsureDataDir().Return(dataDir, nil).MinTimes(1)
	mgrExp.WithLogFuncOption().Return(nil)
	mgrExp.WithTracingOption().Return(nil)

	// If this is a loopback preferred node, we do not invoke the TLS or
	// cluster options.
	mgrExp.IsExistingNode().Return(true, nil).Times(2)
	mgrExp.IsLoopbackPreferred().Return(true).Times(2)
	gomock.InOrder(
		mgrExp.IsLoopbackBound(gomock.Any()).Return(false, nil),
		mgrExp.IsLoopbackBound(gomock.Any()).Return(true, nil),
	)

	// Ensure that we expect a clean startup and shutdown.
	s.expectNodeStartupAndShutdown()

	s.hub.EXPECT().Subscribe(apiserver.DetailsTopic, gomock.Any()).Return(func() {}, nil)

	s.client.EXPECT().Cluster(gomock.Any()).Return(nil, nil)

	w := s.newWorker(c)
	defer workertest.DirtyKill(c, w)
	dbw := w.(*dbWorker)

	ensureStartup(c, dbw)

	// At this point we have started successfully.
	// Push a message onto the API details channel to simulate changes.
	select {
	case dbw.apiServerChanges <- apiserver.Details{
		Servers: map[string]apiserver.APIServer{
			"0": {ID: "0", InternalAddress: "127.0.0.1:1234"},
		},
	}:
	case <-time.After(testing.LongWait):
		c.Fatal("timed out waiting for cluster change to be processed")
	}

	err := workertest.CheckKilled(c, w)
	c.Assert(errors.Is(err, dependency.ErrBounce), jc.IsTrue)
}