Howto indicate all items in a collection are NotNull with ContractAnnotation Follow

If i have an simple class as below containing a collection where i know that the collection can never have null added to it, is there any way to tell resharper this so that i would not get a warning on the indicated line (item may be null).

At the moment i tend to put a Debug.Assert(item!=null) wich prevents the warning on debug build with no release overhead. Other than that i could wrap all the standard collection types with wrapper classes or use an IEnumerator<T> extension (e.g. foreach (var item in items.WithNoNulls()) but this all seems a bit messy just to remove the resharper warnings.

public class MyClass
{
    [NotNull] private readonly List<IMapItem> items = new List<IMapItem>();
 
    public void Add([NotNull] IMapItem item)
    {
        items.Add(item);
    }
 
    private void DoWord()
    {
        foreach (var item in items)
        {
            string s = item.Name;
        }
    }
}