code: func InTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
  	return globalBus.InTransaction(ctx, fn)
  }
docs: // InTransaction starts a transaction and store it in the context.
  // The caller can then pass a function with multiple DispatchCtx calls that
  // all will be executed in the same transaction. InTransaction will rollback if the
  // callback returns an error.