using System;
using System.Linq;
using System.Collections.Generic;

public class Test
{
	private static readonly List<string> listOne = new List<string> { "one", "1" };
	private static readonly List<string> listTwo = new List<string> { "two", "2" };
	
	public static void Main()
	{
		PrintList(listOne);
		Foo(listOne);
		PrintList(listOne);

		PrintList(listTwo);
		Foo(listTwo.ToList());
		PrintList(listTwo);
	}
	
	private static void Foo<T>(List<T> list)
	{
		list.Clear();
	}
	
	private static void PrintList<T>(List<T> list)
	{
		Console.WriteLine(list.Any() ? string.Join(",", list) : "(empty list)");
	}
}