code: public function down()
      {
          $authManager = $this->getAuthManager();
          $this->db = $authManager->db;
  
          if ($this->isMSSQL()) {
              $this->execute('DROP TRIGGER {$schema}.trigger_auth_item_child;');
          }
  
          $this->dropTable($authManager->assignmentTable);
          $this->dropTable($authManager->itemChildTable);
          $this->dropTable($authManager->itemTable);
          $this->dropTable($authManager->ruleTable);
      }
docs: {@inheritdoc}