code: func New(authRequestHandlers ...authenticator.Request) authenticator.Request {
  	if len(authRequestHandlers) == 1 {
  		return authRequestHandlers[0]
  	}
  	return &unionAuthRequestHandler{Handlers: authRequestHandlers, FailOnError: false}
  }
docs: // New returns a request authenticator that validates credentials using a chain of authenticator.Request objects.
  // The entire chain is tried until one succeeds. If all fail, an aggregate error is returned.