code: func (b *batchSpendReporter) FailRemaining(err error) error {
  	for outpoint, requests := range b.requests {
  		b.notifyRequests(&outpoint, requests, nil, err)
  	}
  	return err
  }
docs: // FailRemaining will return an error to all remaining requests in the event we
  // experience a critical rescan error. The error is threaded through to allow
  // the syntax:
  //     return reporter.FailRemaining(err)