public void Malformed_Weird()
        {
            var empty                  = new EmptyEnumerable <int>();
            var emptyOrdered           = new EmptyOrderedEnumerable <int>();
            var groupByDefault         = new GroupByDefaultEnumerable <int, int, int, EmptyEnumerable <int>, EmptyEnumerator <int> >();
            var groupBySpecific        = new GroupBySpecificEnumerable <int, int, int, EmptyEnumerable <int>, EmptyEnumerator <int> >();
            var lookupDefault          = new LookupDefaultEnumerable <int, int>();
            var lookupSpecific         = new LookupSpecificEnumerable <int, int>();
            var range                  = new RangeEnumerable();
            var repeat                 = new RepeatEnumerable <int>();
            var reverseRange           = new ReverseRangeEnumerable();
            var oneItemDefault         = new OneItemDefaultEnumerable <int>();
            var oneItemSpecific        = new OneItemSpecificEnumerable <int>();
            var oneItemDefaultOrdered  = new OneItemDefaultOrderedEnumerable <int>();
            var oneItemSpecificOrdered = new OneItemSpecificOrderedEnumerable <int>();

            // empty
            {
                try { empty.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // emptyOrdered
            {
                try { emptyOrdered.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // groupByDefault
            {
                try { groupByDefault.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // groupBySpecific
            {
                try { groupBySpecific.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // lookupDefault
            {
                try { lookupDefault.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // lookupSpecific
            {
                try { lookupSpecific.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // range
            {
                try { range.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // repeat
            {
                try { repeat.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // reverseRange
            {
                try { reverseRange.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // oneItemDefault
            {
                try { oneItemDefault.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // oneItemSpecific
            {
                try { oneItemSpecific.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // oneItemDefaultOrdered
            {
                try { oneItemDefaultOrdered.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }

            // oneItemSpecificOrdered
            {
                try { oneItemSpecificOrdered.AsEnumerable(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); }
            }
        }