/**
  * Checks whether the current FE user (if any is logged in) could register
  * for the current event, not checking the event's vacancies yet.
  * So this function only checks whether the user is logged in and isn't blocked for the event's duration yet.
  *
  * Note: This function does not check whether a logged-in front-end user fulfills all requirements for an event.
  *
  * @param tx_seminars_seminar $seminar a seminar for which we'll check if it is possible to register
  *
  * @return bool TRUE if the user could register for the given event, FALSE otherwise
  */
 private function couldThisUserRegister(tx_seminars_seminar $seminar)
 {
     // A user can register either if the event allows multiple registrations
     // or the user isn't registered yet and isn't blocked either.
     return $seminar->allowsMultipleRegistrations() || !$this->isUserRegistered($seminar) && !$this->isUserBlocked($seminar);
 }