Does C# have IsNullOrEmpty for List/IEnumerable?

Question

I know generally empty List is more prefer than NULL. But I am going to return NULL, for mainly two reasons

1. I have to check and handle null values explicitly,

Answer 1

I modified the suggestion from Matthew Vines to avoid the "Possible multiple enumeration of IEnumerable" - problem. (see also the comment from Jon Hanna)

public static bool IsNullOrEmpty(this IEnumerable items)
    => items == null
    || (items as ICollection)?.Count == 0
    || !items.GetEnumerator().MoveNext();

... and the unit test:

[Test]
public void TestEnumerableEx()
{
    List list = null;
    Assert.IsTrue(list.IsNullOrEmpty());

    list = new List();
    Assert.IsTrue(list.IsNullOrEmpty());

    list.AddRange(new []{1, 2, 3});
    Assert.IsFalse(list.IsNullOrEmpty());

    var enumerator = list.GetEnumerator();
    for(var i = 1; i <= list.Count; i++)
    {
        Assert.IsFalse(list.IsNullOrEmpty());
        Assert.IsTrue(enumerator.MoveNext());
        Assert.AreEqual(i, enumerator.Current);
    }

    Assert.IsFalse(list.IsNullOrEmpty());
    Assert.IsFalse(enumerator.MoveNext());
}