// PutBucket
		router.Methods(http.MethodPut).
			HandlerFunc(s3APIMiddleware(api.PutBucketHandler))
		// HeadBucket
		router.Methods(http.MethodHead).
			HandlerFunc(s3APIMiddleware(api.HeadBucketHandler))
		// PostPolicy
		router.Methods(http.MethodPost).
			MatcherFunc(func(r *http.Request, _ *mux.RouteMatch) bool {
				return isRequestPostPolicySignatureV4(r)
			}).

}

func registerBucketLevelFunc(bucket *mux.Router, api objectAPIHandlers, apiFunctions ...string) {
	for _, apiFunction := range apiFunctions {
		switch apiFunction {
		case "PostPolicy":
			// Register PostPolicy handler.
			bucket.Methods(http.MethodPost).HeadersRegexp("Content-Type", "multipart/form-data*").HandlerFunc(api.PostPolicyBucketHandler)
		case "HeadObject":
			// Register HeadObject handler.