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: collectionopt_test.go
    path of file: ./repos/learning/golang/practice/go-crontab/gopath/src/github.com/mongodb/mongo-go-driver/mongo/collectionopt
    
    the code of the file until where you have to start completion: package collectionopt

import (
	"testing"

	"github.com/mongodb/mongo-go-driver/core/readconcern"
	"github.com/mongodb/mongo-go-driver/core/readpref"
	"github.com/mongodb/mongo-go-driver/core/writeconcern"
	"github.com/mongodb/mongo-go-driver/internal/testutil/helpers"
)

var rcLocal = readconcern.Local()
var rcMajority = readconcern.Majority()

var wc1 = writeconcern.New(writeconcern.W(10))
var 
    
func createNestedBundle3(t *testing.T) *CollectionBundle {
	b1 := BundleCollection(ReadConcern(rcMajority))
	testhelpers.RequireNotNil(t, b1, "b1 was nil")

	b2 := BundleCollection(WriteConcern(wc1), b1)
	testhelpers.RequireNotNil(t, b2, "b1 was nil")

	b3 := BundleCollection(ReadPreference(rpPrimary))
	testhelpers.RequireNotNil(t, b3, "b1 was nil")

	b4 := BundleCollection(WriteConcern(wc2), b3)
	testhelpers.RequireNotNil(t, b4, "b1 was nil")

	outer := BundleCollection(b4, WriteConcern(wc1), b2)
	testhelpers.RequireNotNil(t, outer, "b1 was nil")

	return outer
}