issues storing access token in session

[gonsalvg]

Heyo, stuck again with another question. Once again, not a PHP expert, but I think this should be working as I have it set up.

$_SESSION['graph_token']= $token;

fetching token from session gives an error for incomplete class - issue restoring the class from session

trying to instance accesstoken from the library using the token string (from token->gettoken)and now I get
"expires" is not set on the token when trying to use it.

[Acsiod]

$_SESSION['graph_token']= serialize($token);

Then

if(isset($_SESSION['graph_token']))
{$token = unserialize($_SESSION['graph_token']);}