/**
  * @param int $presentation_id
  * @return void
  */
 public function removePresentation($presentation_id)
 {
     $this->tx_manager->transaction(function () use($presentation_id) {
         $presentation = $this->presentation_repository->getById($presentation_id);
         if (is_null($presentation)) {
             throw new NotFoundEntityException(sprintf('presentation id %s', $presentation_id));
         }
         if (!$presentation->canDelete()) {
             throw new EntityValidationException('you cant delete this presentation!');
         }
         $this->presentation_repository->delete($presentation);
     });
 }