[Fact]
        public void FetchXml_Aggregate_GroupByOptionset_Count()
        {
            var fetchXml = @"<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false' aggregate='true'>
                              <entity name='contact'>
                                    <attribute name='contactid' alias='count.contacts' aggregate='count' />
                                    <attribute name='gendercode' alias='group.gendercode' groupby='true' />
                                  </entity>
                            </fetch>";

            var male = new OptionSetValue(1);
            var female = new OptionSetValue(2);

            var ctx = new XrmFakedContext();
            ctx.Initialize(new[] {
                new Contact() { Id = Guid.NewGuid(), GenderCode = male, FirstName = "John" },
                new Contact() { Id = Guid.NewGuid(), GenderCode = female, FirstName = "Jane" },
                new Contact() { Id = Guid.NewGuid(), GenderCode = male, FirstName = "Sam" },
                new Contact() { Id = Guid.NewGuid(), GenderCode = male, FirstName = "John" },
            });

            var collection = ctx.GetFakedOrganizationService().RetrieveMultiple(new FetchExpression(fetchXml));

            // Make sure we only have the expected properties
            foreach (var e in collection.Entities)
            {
                Assert.Equal(new[] { "count.contacts", "group.gendercode" }, e.Attributes.Keys.OrderBy(x => x));
            }

            Assert.Equal(2, collection.Entities.Count);

            var maleGroup = collection.Entities.SingleOrDefault(x => (male.Value).Equals(x.GetAttributeValue<AliasedValue>("group.gendercode").Value));
            Assert.Equal(3, maleGroup.GetAttributeValue<AliasedValue>("count.contacts").Value);

            var femaleGroup = collection.Entities.SingleOrDefault(x => (female.Value).Equals(x.GetAttributeValue<AliasedValue>("group.gendercode").Value));
            Assert.Equal(1, femaleGroup.GetAttributeValue<AliasedValue>("count.contacts").Value);
        }