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: middleware.go
    path of file: ./repos/moby/vendor/github.com/aws/smithy-go/auth/bearer
    
    the code of the file until where you have to start completion: package bearer

import (
	"context"
	"fmt"

	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Message is the middleware stack's request transport message value.
type Message interface{}

// Signer provides an interface for implementations to decorate a request
// message with a bearer token. The signer is responsible f
    
func (SignHTTPSMessage) SignWithBearerToken(ctx context.Context, token Token, message Message) (Message, error) {
	req, ok := message.(*smithyhttp.Request)
	if !ok {
		return nil, fmt.Errorf("expect smithy-go HTTP Request, got %T", message)
	}

	if !req.IsHTTPS() {
		return nil, fmt.Errorf("bearer token with HTTP request requires HTTPS")
	}

	reqClone := req.Clone()
	reqClone.Header.Set("Authorization", "Bearer "+token.Value)

	return reqClone, nil
}