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: common.go
    path of file: ./repos/cloud-torrent/vendor/github.com/shirou/gopsutil/internal/common
    
    the code of the file until where you have to start completion: //
// gopsutil is a port of psutil(http://pythonhosted.org/psutil/).
// This covers these architectures.
//  - linux (amd64, arm)
//  - freebsd (amd64)
//  - windows (amd64)
package common

import (
	"bufio"
	"errors"
	"io/ioutil"
	"net/url"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"reflect"
	"runtime"
	"strc
    
func GetEnv(key string, dfault string, combineWith ...string) string {
	value := os.Getenv(key)
	if value == "" {
		value = dfault
	}

	switch len(combineWith) {
	case 0:
		return value
	case 1:
		return filepath.Join(value, combineWith[0])
	default:
		all := make([]string, len(combineWith)+1)
		all[0] = value
		copy(all[1:], combineWith)
		return filepath.Join(all...)
	}
	panic("invalid switch case")
}