public async Task PostAiMove_GameInCache_ReturnsAccepted()
{
var actionResult = await _controller.AiMove(TestHelpers.ExistingGameId, 1);
var result = actionResult.Should().BeOfType <AcceptedResult>().Subject;
result.Location.Should().Be($"/game/{TestHelpers.ExistingGameId}");
result.Value.Should().BeAssignableTo <GameState>();
}