code: func (c *Client) ListUnspentMinMaxAddressesAsync(minConf, maxConf int, addrs []btcutil.Address) FutureListUnspentResult {
  	addrStrs := make([]string, 0, len(addrs))
  	for _, a := range addrs {
  		addrStrs = append(addrStrs, a.EncodeAddress())
  	}
  
  	cmd := btcjson.NewListUnspentCmd(&minConf, &maxConf, &addrStrs)
  	return c.sendCmd(cmd)
  }
docs: // ListUnspentMinMaxAddressesAsync 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 ListUnspentMinMaxAddresses for the blocking version and more details.