Are Angular2's services supposed to be stateless? : <p>I come from Java world where services are commonly meant to be stateless. Should be services in Angular2 also stateless? Or can we simply store the state, because we do not have to care about concurrent thread access as in Java example?</p>

<p>At <a href="https://angular.io/docs/ts/latest/guide/router.html#!#teach-authguard-to-authenticate" rel="noreferrer">https://angular.io/docs/ts/latest/guide/router.html#!#teach-authguard-to-authenticate</a> in AuthService class the state is stored.</p>

<p>Is it just to simplify the example or is it a common practice? I know that services are instantiated and live for the scope where they are declared, but that would mean that I would have to care where the service has been provided to know how long the state lasts.</p>
