Assert.IsEmpty tests that a string or collection is not empty.

Assert.IsNotEmpty(string aString, string message=null, params object[] args);
Assert.IsNotEmpty(IEnumerable aCollection, string message=null, params object[] args);

You may use Assert.That to achieve the same result. The two statements below are equivalent:

Assert.IsNotEmpty(someCollection);
Assert.That(someCollection, Is.Not.Empty);