code: func (c *Client) LoadTxFilterAsync(reload bool, addresses []btcutil.Address,
  	outPoints []wire.OutPoint) FutureLoadTxFilterResult {
  
  	addrStrs := make([]string, len(addresses))
  	for i, a := range addresses {
  		addrStrs[i] = a.EncodeAddress()
  	}
  	outPointObjects := make([]btcjson.OutPoint, len(outPoints))
  	for i := range outPoints {
  		outPointObjects[i] = btcjson.OutPoint{
  			Hash:  outPoints[i].Hash.String(),
  			Index: outPoints[i].Index,
  		}
  	}
  
  	cmd := btcjson.NewLoadTxFilterCmd(reload, addrStrs, outPointObjects)
  	return c.sendCmd(cmd)
  }
docs: // LoadTxFilterAsync returns an instance of a type that can be used to
  // get the result of the RPC at some future time by invoking the Receive
  // function on the returned instance.
  //
  // See LoadTxFilter for the blocking version and more details.
  //
  // NOTE: This is a btcd extension ported from github.com/decred/dcrrpcclient
  // and requires a websocket connection.