title: Facebook android sdk 3.0 SSO
body: <p>In previous versions of the Facebook SDK we could check if a user is still signed in by using tokens. In the new 3.0 version I can't find another way other than invoking <code>openSession()</code> to check if the user is still logged in with <code>SSO</code>. But <code>openSession()</code> automatically invokes the login if the user is not saved and I don't want that. I only want to check SSO. How do I do this?</p>