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: config.go
    path of file: ./repos/traefik/pkg/testhelpers
    
    the code of the file until where you have to start completion: package testhelpers

import (
	"github.com/traefik/traefik/v3/pkg/config/dynamic"
)

// BuildConfiguration is a helper
    
func WithService(name string, opts ...func(*dynamic.ServersLoadBalancer)) func(*dynamic.ServersLoadBalancer) string {
	return func(r *dynamic.ServersLoadBalancer) string {
		for _, opt := range opts {
			opt(r)
		}
		return name
	}
}