public void NotEqualToTest()
        {
            SearchFilter filter = new SearchFilter.NotEqualTo(
                MessageObjectSchema.Body,
                "test body");

            Assert.AreEqual(
                filter.FilterOperator,
                FilterOperator.ne);

            Assert.AreEqual(
                "$filter=Body ne 'test body'"
                , filter.Query);
        }
        public void TestSearchFilterCollection()
        {
            SearchFilter lessThanOrEqualTo = new SearchFilter.IsLessThanOrEqualTo(
                MailFolderObjectSchema.TotalItemCount,
                5);

            SearchFilter greaterThan = new SearchFilter.IsGreaterThan(
                MessageObjectSchema.CreatedDateTime,
                new DateTimeOffset(new DateTime(2019, 2, 1)));

            SearchFilter notEqualTo = new SearchFilter.NotEqualTo(
                MessageObjectSchema.Body,
                "test body");

            SearchFilter.SearchFilterCollection searchFilterCollection = new SearchFilter.SearchFilterCollection(
                FilterOperator.and,
                lessThanOrEqualTo,
                greaterThan,
                notEqualTo);

            Assert.AreEqual(
                FilterOperator.and,
                searchFilterCollection.FilterOperator);

            Assert.AreEqual(
                "$filter=TotalItemCount le 5 and CreatedDateTime gt 2019-02-01T12:00:00Z and Body ne 'test body'",
                searchFilterCollection.Query);

            Assert.ThrowsException <ArgumentException>(() =>
            {
                searchFilterCollection = new SearchFilter.SearchFilterCollection(FilterOperator.ge);
            });

            searchFilterCollection = new SearchFilter.SearchFilterCollection(
                FilterOperator.or,
                lessThanOrEqualTo,
                greaterThan,
                notEqualTo);

            Assert.AreEqual(
                FilterOperator.or,
                searchFilterCollection.FilterOperator);

            Assert.AreEqual(
                "$filter=TotalItemCount le 5 or CreatedDateTime gt 2019-02-01T12:00:00Z or Body ne 'test body'",
                searchFilterCollection.Query);
        }