Simple resetting cache

Cache.cs

using System.Collections.Generic;

public class ReloadingCache
    {
        private List<string> _cachedItems;
        private System.Threading.Timer _timer;

        public ReloadingCache()
        {
            //Load the first lot of data to stop consumers getting null
            _cachedItems = MyMethodThatGivesMeTheList();
            //Create a timer that will be called after 30k ms (30seconds)
            //It will not fire again after that until you call change
            _timer = new System.Threading.Timer(state =>
            {
                //Load our new list
                var newList = MyMethodThatGivesMeTheList();
                //Swap the new list for the old list, ensuring that the swap is atomic
                //you really don't want 1/2 a pointer
                System.Threading.Interlocked.Exchange(ref _cachedItems, newList);
                
                //Set the timer to fire 1 more time in another 30 seconds
                _timer.Change(30000, System.Threading.Timeout.Infinite);
            }, null, 30000, System.Threading.Timeout.Infinite);
        }

        public List<string> GetListToDoWork()
        {
            //Ensure we have the lastest pointer to our list and not a cached one
            //so we use the volatile read method (otherwise we might read the old
            //one for a while
            return System.Threading.Volatile.Read(ref _cachedItems);
        }
        
        private List<string> MyMethodThatGivesMeTheList()
        {
            return new List<string>()
            {
                "Test1",
                "Test2"
            };
        }
    }