public void CountTest()
        {
            //expected
            int        expected   = 1;
            bool       called     = false;
            Volary     volary     = new Volary();
            VolaryStub volaryStub = new VolaryStub();

            volary.volary = volaryStub;

            Mock.Arrange(() => volaryStub.Count()).DoInstead(() => called = true);

            // actual
            int actual = volary.Count();

            Assert.AreEqual(expected, actual);
        }