How to create method with optional arguments in Method Binding?

[KiddoV]

For example, I got this in Go:

func (a *App) Greeting(name string, addr... string) string {
    addrStr := ""
    if len(addr) > 0 {
        addrStr = addr[0]
    } else {
        addrStr = "Unknown"
    }
    return fmt.Sprintf("Hello %s, who came from %s!", name, addrStr)
}

Which currently generate binding like:

export function Greeting(arg1:string, arg2:string[]):Promise<string>;

I am expecting something like:

export function Greeting(arg1:string, arg2?:string):Promise<string>;

so I can call it in JS/TS like:

app.Greeting("Name");
//or
app.Greeting("Name", "My Address");

Is it possible at the moment?