code: func (v *Validator) Validate(h http.Handler) http.Handler {
  	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
  		if err := v.ValidRequest(r); err != nil {
  			http.Error(w, "", http.StatusUnauthorized)
  			return
  		}
  		h.ServeHTTP(w, r)
  	})
  }
docs: // Validate is a handler wrapper that takes care of the signature validation of
  // incoming requests and rejects them if invalid or pass them on to your handler
  // otherwise.