/**
  * Delete all delivered files of user
  *
  * @param int $a_user_id user id
  */
 function deleteAllDeliveredFilesOfUser($a_user_id)
 {
     include_once "./Customizing/global/plugins/Services/Repository/RepositoryObject/Ephorus/classes/class.ilEphAssignment.php";
     ilEphAssignment::deleteAllDeliveredFilesOfUser($this->getId(), $a_user_id);
 }