code: func (c *Client) AddMultisigAddress(requiredSigs int, addresses []btcutil.Address, account string) (btcutil.Address, error) {
  	return c.AddMultisigAddressAsync(requiredSigs, addresses,
  		account).Receive()
  }
docs: // AddMultisigAddress adds a multisignature address that requires the specified
  // number of signatures for the provided addresses to the wallet.