protected override void OnSaveT(Document input, Stream output, PropertyBasedSaveConfigToken token, Surface scratchSurface, ProgressEventHandler progressCallback)
        {
            PSPFile file = new PSPFile();

            CompressionFormats format  = (CompressionFormats)token.GetProperty(PropertyNames.CompressionType).Value;
            FileVersion        version = (FileVersion)token.GetProperty(PropertyNames.FileVersion).Value;

            file.Save(input, output, format, scratchSurface, (ushort)version, progressCallback);
        }
        protected override Document OnLoad(Stream input)
        {
            PSPFile file = new PSPFile();

            return(file.Load(input));
        }