code: func (c *Client) SendToAddressComment(address btcutil.Address, amount btcutil.Amount, comment, commentTo string) (*chainhash.Hash, error) {
  	return c.SendToAddressCommentAsync(address, amount, comment,
  		commentTo).Receive()
  }
docs: // SendToAddressComment sends the passed amount to the given address and stores
  // the provided comment and comment to in the wallet.  The comment parameter is
  // intended to be used for the purpose of the transaction while the commentTo
  // parameter is indended to be used for who the transaction is being sent to.
  //
  // The comments are not part of the transaction and are only internal
  // to the wallet.
  //
  // See SendToAddress to avoid using comments.
  //
  // NOTE: This function requires to the wallet to be unlocked.  See the
  // WalletPassphrase function for more details.