src/MockStorage.php
public function lock(string $sessionIdentifier): bool
    {
        if (in_array($sessionIdentifier, self::$lockedIdentifiers)) {
            return true;
        }

        self::$lockedIdentifiers[] = $sessionIdentifier;

        return true;
    }
public function lock(string $sessionIdentifier): bool
    {
        if (in_array($sessionIdentifier, self::$lockedIdentifiers)) {
            return true;
        }

        self::$lockedIdentifiers[] = $sessionIdentifier;

        return true;
    }
public function lock ( string $ sessionIdentifier ) : bool { if ( in_array ( $ sessionIdentifier , self :: $ lockedIdentifiers ) ) { return true ; } self :: $ lockedIdentifiers [ ] = $ sessionIdentifier ; return true ; }
Asks the drive to lock the session storage

@param string $sessionIdentifier The session identifier to be locked
@return bool
Asks the drive to lock the session storage