public async Task GiveUpForMatch_ShouldNotSave_WhenMatchDoesNotExist()
        {
            // Arrange
            var responseMessage = "Specified match doesn't exist!";

            _unitOfWorkMock.Setup(x => x.Matchdays.GetById(It.IsAny <int>()))
            .ReturnsAsync(() => null);

            // Act
            var result = await _sut.GiveUpForMatch(It.IsAny <int>(), It.IsAny <int>());

            // Assert
            Assert.Equal(responseMessage, result.Value);
        }