public void GetFileContentIdDoesntExists(string id)
        {
            FakeDBManager fakeDatabase = new FakeDBManager();

            Assert.AreEqual("INVALID", fakeDatabase.GetFileContentId(id));
        }
        public void DeltaDoesntExists(string id)
        {
            FakeDBManager fakeDatabase = new FakeDBManager();

            Assert.AreEqual(false, fakeDatabase.DeltaExists(id));
        }