public void GetEnumerator_WhenCalled_ReturnsCorrectly()
        {
            // arrange
            var sut = new CacheableDataReader(actualDataReader);

            // act
            var actual = sut.GetEnumerator();

            // assert
            Assert.That(actual, Is.Not.Null);                            // <- only sane thing to check directly?
            Assert.That(sut.Cast<IDataRecord>().Count(), Is.EqualTo(1)); // <- implies GetEnumerator, probably brittle
        }