using System.Collections.Generic;
public static void Main()
var testList = new List<int>() { 1, 2 };
SwapListPositions(testList, 0, 1);
Console.WriteLine(testList[0]);
Console.WriteLine(testList[1]);
internal static void SwapListPositions<T>(IList<T> list, int index1, int index2)
list[index1] = list[index2];