You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.go
    path of file: ./repos/gotalk/examples/tls
    
    the code of the file until where you have to start completion: // demonstrates how to use gotalk over encrypted connections (TLS)
package main

import "os"

// Describes the request parameter and operation result types for our "greet" operation
type GreetIn struct {
	Name string `json:"name"`
}

type GreetOut struct {
	Greeting string `json:"greeting"`
}

func main() {
	mode := "demo"
	if len(os.Args) > 1 {
		mode = os.Args[1]
		if len(os.Args) > 2 || (mode != "client" && mode != "server") {
			println("usage:")
    
func main() {
	mode := "demo"
	if len(os.Args) > 1 {
		mode = os.Args[1]
		if len(os.Args) > 2 || (mode != "client" && mode != "server") {
			println("usage:")
			println("  " + os.Args[0] + "         Run full demo and exit")
			println("  " + os.Args[0] + " server  Run demo server")
			println("  " + os.Args[0] + " client  Run demo client and exit")
			println("  " + os.Args[0] + " -h      Print help and exit")
			os.Exit(1)
		}
	}

	port := "1234"

	if mode == "server" || mode == "demo" {
		server(port)
	}

	if mode == "client" || mode == "demo" {
		client(port)
	} else {
		<-make(chan bool) // wait forever, until ^C
	}
}