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/goHackTools/projects/56_PerformingConcurrentScanning
    
    the code of the file until where you have to start completion: package main

import (
	"fmt"
	"log"
	"net"
	"os"
	"sort"
	"time"

	"github.com/briandowns/spinner"
)

func main() {
	if len(os.Args) == 1 || os.Args[1] == "-h" {
		usage(os.Args[0])
	}

	s := spinner.New(spinner.CharSets[36], 100*time.Millisecond) // Build our new spinner

	err := s.Color("red")
	if err != nil {
		log.Println(err)
	}

	target :=
    
func main() {
	if len(os.Args) == 1 || os.Args[1] == "-h" {
		usage(os.Args[0])
	}

	s := spinner.New(spinner.CharSets[36], 100*time.Millisecond) // Build our new spinner

	err := s.Color("red")
	if err != nil {
		log.Println(err)
	}

	target := os.Args[1]
	ports := make(chan int, 100)
	results := make(chan int)

	s.Start()

	var openports []int

	for i := 0; i < cap(ports); i++ {
		go worker(ports, results, target)
	}

	go func() {
		for i := 1; i <= 1024; i++ {
			ports <- i
		}
	}()

	for i := 0; i < 1024; i++ {
		port := <-results
		if port != 0 {
			openports = append(openports, port)
		}
	}

	close(ports)
	close(results)

	sort.Ints(openports)
	fmt.Println()

	for _, port := range openports {
		fmt.Printf("%d open\n", port)
	}

	s.Stop()
}