Multiple variables in a using statement

Here’s a simple file copy program:using System;using System.IO; public class FileCopy{    private static void Main(string[] args)    {        if (args.Length != 2)        {            Console.WriteLine("Usage: filecopy ");            return;        }        Copy(args[0], args[1]);    }    private static void Copy(string source, string destination)    {        const int