code: func (r FutureVersionResult) Receive() (map[string]btcjson.VersionResult,
  	error) {
  	res, err := receiveFuture(r)
  	if err != nil {
  		return nil, err
  	}
  
  	// Unmarshal result as a version result object.
  	var vr map[string]btcjson.VersionResult
  	err = json.Unmarshal(res, &vr)
  	if err != nil {
  		return nil, err
  	}
  
  	return vr, nil
  }
docs: // Receive waits for the response promised by the future and returns the version
  // result.
  //
  // NOTE: This is a btcsuite extension ported from
  // github.com/decred/dcrrpcclient.