public void Test_WithoutElement_String_WithCompare()
        {
            var forFirstCompare = new FirstCharEqualityComparer();
            var sequence        = new[] { "one", "two", "three" };
            var result          = sequence.WithoutElement("five", forFirstCompare);

            result.Should().BeEquivalentTo(new[] { "one", "two", "three" });
        }
        public void Test_WithoutElement_String_WithNull_WithCompare2()
        {
            var forFirstCompare = new FirstCharEqualityComparer();
            var sequence        = new[] { null, "two", "three" };
            var result          = sequence.WithoutElement("tWo", forFirstCompare);

            result.Should().BeEquivalentTo(new string[] { null });
        }