public async Task Get_Cards_WhenCalled_With_A_CardName_Should_Return_FileContentResult()
{
// Arrange
const string cardName = "Blue-Eyes White Dragon";
_mediator.Send(Arg.Any <IRequest <CardImageByNameResult> >()).Returns(new CardImageByNameResult {
ContentType = "image/jpeg", Image = new byte[] { 1, 2, 3, 4, 5 }
});
// Act
var result = await _sut.Cards(cardName);
// Assert
result.Should().BeOfType <FileContentResult>();
}