how to use get..() method from userinfo

[sKuD sKuD]

Hi , 

when I try this : 

$oauth2 = new apiOauth2Service($client);

$userInfo = $oauth2->userinfo->get();

echo $userInfo->getEmail();

I have this error : string(171) "ERROR : [8] Trying to get property of non-object

These methods are not implemented ? I must only use the userinfo array ?

Thanks !!!