public async Task Handler_Erro()
        {
            int number = -45;

            _mediator.Setup(m => m.Send(It.IsAny <GetDividersQuery>(), new CancellationToken()))
            .ReturnsAsync(new DividersResponse(number));

            var command = new GetDividersQuery(number);

            var result = await _mediator.Object.Send(command);

            Assert.IsType <DividersResponse>(result);
            Assert.Empty(result.Dividers);
        }
        public async Task Handler_Sucesso()
        {
            int number   = 45;
            var expected = new List <int>()
            {
                1, 3, 5, 9, 15, 45
            };

            _mediator.Setup(m => m.Send(It.IsAny <GetDividersQuery>(), new CancellationToken()))
            .ReturnsAsync(new DividersResponse(number));

            var command = new GetDividersQuery(number);

            var result = await _mediator.Object.Send(command);

            Assert.IsType <DividersResponse>(result);
            Assert.Equal(expected, result.Dividers);
        }