What is the correct way to get the app instance ($f7) from a helper module?

Since the $f7 var is only available in the component (ex. home.f7.html), what is the correct way to get it from a module file?

Is this the right way to do so? Or is there something easier or better way of getting the app instance?

//my-helper-module.js
export default class Helper {
    showLoginScreen() {
        Framework7.instance.loginScreen.open('#my-login-screen');
    }
}