original_string: public function delete_all_overrides() {
          global $DB;
  
          $overrides = $DB->get_records('lesson_overrides', array('lessonid' => $this->properties->id), 'id');
          foreach ($overrides as $override) {
              $this->delete_override($override->id);
          }
      }
code: public function delete_all_overrides() {
          global $DB;
  
          $overrides = $DB->get_records('lesson_overrides', array('lessonid' => $this->properties->id), 'id');
          foreach ($overrides as $override) {
              $this->delete_override($override->id);
          }
      }
code_tokens: public function delete_all_overrides ( ) { global $ DB ; $ overrides = $ DB -> get_records ( 'lesson_overrides' , array ( 'lessonid' => $ this -> properties -> id ) , 'id' ) ; foreach ( $ overrides as $ override ) { $ this -> delete_override ( $ override -> id ) ; } }
docstring: Deletes all lesson overrides from the database and clears any corresponding calendar events
docstring_tokens: Deletes all lesson overrides from the database and clears any corresponding calendar events