public void RemoveDuplicateSixLetterStrings()
        {
            var strings = SampleStringsStub.DuplicateSixLetterStrings();

            var result = StringFilter.SixLetterStrings(strings);

            Assert.IsTrue(result.Count == 2);
            Assert.AreEqual("albums", result.ElementAt(0));
            Assert.AreEqual("barely", result.ElementAt(1));
        }