How to pass request.user to triggers from cloud functions?

When I call a function from android sdk, I saw logged in user in cloud code logs. And request.user returns the user that run cloud functions. But for example If I write a new object from cloud code, Request.user is undefined in cloud triggers such as BeforeSave? How to pass Request.User to triggers from cloud code?

The user should also be available in triggers. Do you mind to open an issue in GitHub repo with a failing test?