OCA\Richdocuments\Controller\SessionController::loadMember PHP Method

    protected function loadMember($memberId, $expectedEsId = null)
    {
        if (!$memberId) {
            throw new \Exception('Member id can not be empty');
        }
        $member = new Db\Member();
        $member->load($memberId);
        //check if member belongs to the session
        if (!is_null($expectedEsId) && $expectedEsId !== $member->getEsId()) {
            throw new \Exception($memberId . ' does not belong to session ' . $expectedEsId);
        }
        return $member;
    }