public function getUserByEMail(string $email)
    {
        $retval = null;

        if (strlen($email) > 0) {
            $nb_user = CNabuUser::findByEMail($this, $email);
            if ($nb_user instanceof CNabuUser && $nb_user->validateCustomer($this)) {
                $nb_user->setCustomer($this);
                $retval = $nb_user;
            }
        }

        return $retval;
    }