public void Test()
        {
            Helper.DropAllCollections();

            var country = new Country { Code = "NL", Name = "Holanda" };
            country.Save();
            country = new Country { Code = "UK", Name = "Reino Unido" };
            country.Save();
            country = new Country { Code = "ES", Name = "España" };
            country.Save();

            var col = new CountryCollection {FromPrimary = false};
            col.Find().SetLimit(1);

            Console.WriteLine(col.Cursor.Explain().ToJson());

            Assert.AreEqual(1, col.Count);
            Assert.AreEqual(3, col.Total);

            col = new CountryCollection {FromPrimary = true};
            col.Find().SetLimit(3).SetSortOrder(SortBy<Country>.Ascending(C=>C.Name));              

            Assert.AreEqual(3, col.Count);
            Assert.AreEqual("ES", col.First().Code);

            col.Find(Query<Country>.EQ(C => C.Code, "NL"));

            Assert.AreEqual("NL", col.First().Code);
            Assert.AreEqual("NL", col.Last().Code);

            foreach (Country c in col)
            {

            }

        }