docs: def dry_run(func):
      """Dry run: simulate sql execution."""
      @wraps(func)
      def inner(dry_run, *args, **kwargs):
          ret = func(dry_run=dry_run, *args, **kwargs)
          if not dry_run:
              db.session.commit()
          else:
              db.session.rollback()
          return ret
      return inner