using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var list = new List<int> { 10, 20, 30 };

        var enumerator = list.GetEnumerator();

        enumerator.MoveNext();

        Console.WriteLine(enumerator.Current);

        Apply(e => { e.MoveNext(); Console.WriteLine("I executed this"); }, enumerator);

        Console.WriteLine(enumerator.Current);

        Apply(e => { e.MoveNext(); Console.WriteLine("I executed this"); }, enumerator);

        Console.WriteLine(enumerator.Current);

        //Why isn't the enumerator not advancing?

    }

    static void Apply<T>(Action<T> action, T item)

    {

        action(item);

    }

}