public void Deve_Retornar_Todos_As_Models()
        {
            var chamadas = ((List<Chamada>)Builder<Chamada>.CreateListOfSize(2).Build()).AsQueryable();

            var mockDbSetModel = new Mock<DbSet<Chamada>>();
            mockDbSetModel.As<IQueryable<Chamada>>().Setup(m => m.Provider).Returns(chamadas.Provider);
            mockDbSetModel.As<IQueryable<Chamada>>().Setup(m => m.Expression).Returns(chamadas.Expression);
            mockDbSetModel.As<IQueryable<Chamada>>().Setup(m => m.ElementType).Returns(chamadas.ElementType);
            mockDbSetModel.As<IQueryable<Chamada>>().Setup(m => m.GetEnumerator()).Returns(chamadas.GetEnumerator());

            var mockContexto = new Mock<IDbContexto>();
            mockContexto.Setup(x => x.RetornarDbSet<Chamada>()).Returns(mockDbSetModel.Object);

            var repositorio = new RepositorioBase<Chamada>(mockContexto.Object);

            var models = repositorio.RetornarTodos();

            Assert.AreEqual(2, models.Count());
        }