code: func (c *Client) AddMultisigAddressAsync(requiredSigs int, addresses []btcutil.Address, account string) FutureAddMultisigAddressResult {
  	addrs := make([]string, 0, len(addresses))
  	for _, addr := range addresses {
  		addrs = append(addrs, addr.String())
  	}
  
  	cmd := btcjson.NewAddMultisigAddressCmd(requiredSigs, addrs, &account)
  	return c.sendCmd(cmd)
  }
docs: // AddMultisigAddressAsync 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 AddMultisigAddress for the blocking version and more details.