Prado\Security\TUserManager::getUser PHP Метод

    public function getUser($username = null)
    {
        if ($username === null) {
            $user = new TUser($this);
            $user->setIsGuest(true);
            return $user;
        } else {
            $username = strtolower($username);
            if (isset($this->_users[$username])) {
                $user = new TUser($this);
                $user->setName($username);
                $user->setIsGuest(false);
                if (isset($this->_roles[$username])) {
                    $user->setRoles($this->_roles[$username]);
                }
                return $user;
            } else {
                return null;
            }
        }
    }

 public function testSwitchToGuest()
 {
     $userManager = new TUserManager();
     $userManager->init(self::$config);
     $user = $userManager->getUser('joe');
     $userManager->switchToGuest($user);
     self::assertTrue($user->getIsGuest());
 }