// SignHTTPRequest signs an http.Request struct with authv4 using the given region, service, and credentials.
func SignHTTPRequest(req *http.Request, region, service string, creds *credentials.Credentials) {
	v4.Sign(&aws.Request{
		Service: &aws.Service{
			SigningRegion: region,
			SigningName:   service,
			Config: &aws.Config{
				Credentials: creds,
			},
		},
		HTTPRequest: req,
		Time:        time.Now(),
	})
}
// SignHTTPRequest signs an http.Request struct with authv4 using the given region, service, and credentials.
func SignHTTPRequest(req *http.Request, region, service string, creds *credentials.Credentials, body io.ReadSeeker) {
	v4.Sign(&request.Request{
		Service: serviceinfo.ServiceInfo{
			SigningRegion: region,
			SigningName:   service,
			Config: &aws.Config{
				Credentials: creds,
			},
		},
		HTTPRequest: req,
		Body:        body,
		Time:        time.Now(),
	})
}