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: scanner.go
    path of file: ./repos/goHackTools/projects/03_tcpScanner
    
    the code of the file until where you have to start completion: package main

import (
	"fmt"
	"net"
	"os"
	"strconv"
	"time"
)

const (
	args                  = 2
	seconds time.Duration = 10
)

func main() {
	// справка
	if len(os.Args) != args {
		fmt.Fprintf(os.Stderr, "Using: %s ip-addr\n", os.Args[0])
		os.Exit(1)
	}

	target := os.Args[1]

	activeThreads := 0
	doneChannel := make(chan bool)

	for port := 0; port <= 65535; port++ {

    
func main() {
	// справка
	if len(os.Args) != args {
		fmt.Fprintf(os.Stderr, "Using: %s ip-addr\n", os.Args[0])
		os.Exit(1)
	}

	target := os.Args[1]

	activeThreads := 0
	doneChannel := make(chan bool)

	for port := 0; port <= 65535; port++ {
		go testTCPConnection(target, port, doneChannel)
		activeThreads++
	}
	// Wait for all threads to finish
	for activeThreads > 0 {
		<-doneChannel
		activeThreads--
	}
}