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: receive_pack_test.go
    path of file: ./repos/go-git/plumbing/transport/server
    
    the code of the file until where you have to start completion: package server_test

import (
	"context"

	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/protocol/packp"
	"github.com/go-git/go-git/v5/plumbing/transport"

	fixtures "github.com/go-git/go-git-fixtures/v4"
	. "gopkg.in/check.v1"
)

type ReceivePackSuite struct {
	BaseSuite
}

var _ = Suite(&ReceivePackSuite{})

func (s *ReceivePackSuite) SetUpSuite(c *C) {
	s.BaseSuite.SetUpSuite(c)
	s.ReceivePackSuite.Client = s.client
}

func (s *ReceivePackSuite) SetUpTest(c *C) {
	s.prepareRepositories(c)

    
func (s *ReceivePackSuite) TestReceivePackWithNilPackfile(c *C) {
	endpoint := s.Endpoint
	auth := s.EmptyAuth

	fixture := fixtures.Basic().ByTag("packfile").One()
	req := packp.NewReferenceUpdateRequest()
	req.Commands = []*packp.Command{
		{Name: "refs/heads/newbranch", Old: plumbing.NewHash(fixture.Head), New: plumbing.ZeroHash},
	}
	// default is already nil, but be explicit since this is what the test is for
	req.Packfile = nil

	comment := Commentf(
		"failed with ep=%s fixture=%s",
		endpoint.String(), fixture.URL,
	)

	r, err := s.Client.NewReceivePackSession(endpoint, auth)
	c.Assert(err, IsNil, comment)
	defer func() { c.Assert(r.Close(), IsNil, comment) }()

	report, err := r.ReceivePack(context.Background(), req)
	c.Assert(report, IsNil, comment)
	c.Assert(err, NotNil, comment)
}