LocalFileStoreProvider.cs

public class LocalFileStoreProvider : IFileStoreProvider
{
    public bool SaveScreenshot(FluentSettings settings, byte[] contents, string fileName)
    {
        try
        {
            if (!string.IsNullOrEmpty(settings.ScreenshotPrefix))
            {
                fileName = Path.Combine(
                    Path.GetDirectoryName(fileName),
                    settings.ScreenshotPrefix + Path.GetFileName(fileName));
            }

            if (fileName.Substring(0, fileName.Length - 4) != ".png")
                fileName += ".png";

            File.WriteAllBytes(Path.Combine(settings.ScreenshotPath, fileName), contents);
            return true;
        }
        catch (Exception)
        {
            return false;
        }
    }
}