public void AspectRatio_Verify()
{
var settingWrong1 = new AspectRatio();
var setting = new AspectRatio(FFmpegRatio.Create(1, 1));
Assert.Throws <InvalidOperationException>(() => { var s = settingWrong1.GetAndValidateString(); });
Assert.DoesNotThrow(() => { var s = setting.GetAndValidateString(); });
Assert.Equal(setting.GetAndValidateString(), "-aspect 1:1");
}