OAuth - Realtime Web Apps: With HTML5 WebSocket, PHP, and jQuery - page 264

next, lay out the skeleton of the class by defining all the method names:
abstract class RWA_OAuth
{
public $service_auth_endpoint, $service_token_endpoint, $scope,
$client_id, $client_secret, $client_auth_endpoint,
$id, $username, $name, $email, $profile_image;
protected $logged_in = FALSE,
$access_token = FALSE;
/**
* Checks for a login or logout attempt
*
* @return void
*/
public function __construct( )
{
}
/**
* Checks a login attempt for validity
*
* @return void
* /
public function check_login( )
{
}
/**
* Returns the current logged in state
*
* @return bool The current logged in state
*/
public function is_logged_in( )
{
}
/**
* Processes a logout attempt
*
* @return void
*/
public function logout( )
{
}