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: host.go
    path of file: ./repos/buildkit/vendor/github.com/aws/aws-sdk-go-v2/service/s3/internal/customizations
    
    the code of the file until where you have to start completion: package customizations

import (
	"github.com/aws/smithy-go/transport/http"
	"strings"
)

func updateS3HostFor
    
func updateHostPrefix(req *http.Request, oldEndpointPrefix, newEndpointPrefix string) {
	host := req.URL.Host
	if strings.HasPrefix(host, oldEndpointPrefix) {
		// For example if oldEndpointPrefix=s3 would replace to newEndpointPrefix
		req.URL.Host = newEndpointPrefix + host[len(oldEndpointPrefix):]
	}
}