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: server.go
    path of file: ./repos/platform-samples/api/golang/basics-of-authentication
    
    the code of the file until where you have to start completion: /*
 * Port of server.rb from GitHub "Basics of authentication" developer guide
 * https://developer.github.com
    
func getGitHubClient(accessToken string) *github.Client {
	ctx := background
	ts := oauth2.StaticTokenSource(
		&oauth2.Token{AccessToken: accessToken},
	)
	tc := oauth2.NewClient(ctx, ts)
	return github.NewClient(tc)
}