public static IList<string> GetPaths(FilterQueryOption filterOption, string separator = ".")
        {
            var findAnyAll = new FindNavigationFilterOptions();
            findAnyAll.Find(filterOption.FilterClause.Expression);

            return findAnyAll.GetPaths(separator);
        }
        public void TestFilterVisitor()
        {
            ODataConventionModelBuilder builder = new ODataConventionModelBuilder();
            builder.EntitySet<Bar>("Bar");

            ODataQueryContext context = new ODataQueryContext(builder.GetEdmModel(), typeof(Bar));
            //ODataQueryOptions<Customer> query = new ODataQueryOptions<Customer>(context, new HttpRequestMessage(HttpMethod.Get, "http://server/?$top=10"));

            FilterQueryOption f = new FilterQueryOption("startswith(BarString,'b') eq true", context);
            var fo = new FindNavigationFilterOptions();
            fo.Find(f.FilterClause.Expression);
            List<string> pathsString = fo.GetPaths();
            CollectionAssert.AreEqual(pathsString, new string[0]);

            f = new FilterQueryOption("F/FooId eq 1", context);
            fo = new FindNavigationFilterOptions();
            fo.Find(f.FilterClause.Expression);
            pathsString = fo.GetPaths();
            CollectionAssert.AreEqual(pathsString, new[] { "F" });

            f = new FilterQueryOption("(startswith(BarString,'b') eq true) and (not (Foos/any(x1: x1/B/BarId eq 1)))", context);
            fo = new FindNavigationFilterOptions();
            fo.Find(f.FilterClause.Expression);
            pathsString = fo.GetPaths();
            CollectionAssert.AreEqual(pathsString, new[] { "Foos.B" });

            f = new FilterQueryOption("Foos/any(x1: x1/B/BarId eq 1)", context);
            fo = new FindNavigationFilterOptions();
            fo.Find(f.FilterClause.Expression);
            pathsString = fo.GetPaths();
            CollectionAssert.AreEqual(pathsString, new[] { "Foos.B" });

            f = new FilterQueryOption("F/Bars/any(x1: x1/BarId eq 1)", context);
            fo = new FindNavigationFilterOptions();
            fo.Find(f.FilterClause.Expression);
            pathsString = fo.GetPaths();
            CollectionAssert.AreEqual(pathsString, new[] { "F.Bars" });


        }