Passing Optional Parameter using Go-SDK

[rudreshkoranne]

Hey there everyone!!!

I trying to invoke a Contract's method using the Go-SDK. The Method implementation is such:
public entry fun mint( validator: &signer, avatar_cid: String, public_key: vector<u8>, proxyaddress: Option<address> ) {}

And the Script I have written in go is below:

`func Mint(client aptos.Client, accountaptos.Account, avatarCID string, publicKey crypto.PublicKey, proxyAddress *aptos.AccountAddress) {
pubKeyBytes,  := bcs.Serialize(publicKey)
avatarBytes := []byte(avatarCID)

serializedAvatarBytes,  := bcs.SerializeBytes(avatarBytes)
proxyBytes := []byte{}

if proxyAddress != nil {
    proxyBytes,  = bcs.Serialize(proxyAddress)
}

rawTx, err := client.BuildTransaction(account.Address, aptos.TransactionPayload{
    Payload: &aptos.EntryFunction{
        Module: aptos.ModuleId{
            Address: MODULE_ADDRESS,
            Name:    MODULE_NAME,
        },
        Function: "mint_poa_nft",
        ArgTypes: []aptos.TypeTag{},
        Args: [][]byte{
            serializedAvatarBytes,
            pubKeyBytes,
            proxyBytes,
        },
    },
})}`

now the problem I'm facing is related to the proxy_address which is an optional parameter.
Can anyone please help me this one.