code: def _run_down(self, path, migration, pretend=False):
          
          migration_file = migration["migration"]
  
          instance = self._resolve(path, migration_file)
  
          if pretend:
              return self._pretend_to_run(instance, "down")
  
          if instance.transactional:
              with instance.db.transaction():
                  instance.down()
          else:
              instance.down()
  
          self._repository.delete(migration)
  
          self._note(
              decode("[<info>OK</>] <info>Rolled back</info> ")
              + "<fg=cyan>%s</>" % migration_file
          )
docs: Run "down" a migration instance.