public async void ReturnLeagueWhichExistsInDbByGivenId()
        {
            // Assert
            var league = new League()
            {
                Id      = 1,
                Name    = "Primera Division",
                Country = "Spain",
                Season  = "2018/2019",
                MVP     = new Player()
                {
                    Name = "Lionel", Surname = "Messi"
                },
                Winner = new Team()
                {
                    ShortName = "FC Barcelona"
                }
            };

            LeagueDTO testLeague = null;

            _repositoryMock.Reset();
            _repositoryMock.Setup(r => r.GetByIdAsync(It.IsAny <uint>())).ThrowsAsync(new ArgumentException());
            _repositoryMock.Setup(r => r.GetByIdAsync(1)).ReturnsAsync(league);

            var expectedLeague = _mapper.Map <LeagueDTO>(league);

            // Act
            var err = await Record.ExceptionAsync(async
                                                      () => testLeague = await _service.GetByIdAsync(1));

            // Arrange
            err.Should().BeNull();

            testLeague.Should().NotBeNull();

            testLeague.Should().BeEquivalentTo(expectedLeague);
        }
        public async void ReturnNullWhenLeagueDoNotExistsInDbByGivenId()
        {
            // Assert
            LeagueDTO testLeague = null;

            _repositoryMock.Reset();
            _repositoryMock.Setup(r => r.GetByIdAsync(It.IsAny <uint>())).ReturnsAsync((League)null);

            // Act
            var err = await Record.ExceptionAsync(async
                                                      () => testLeague = await _service.GetByIdAsync(1));

            // Arrange
            err.Should().BeNull();

            testLeague.Should().BeNull();
        }