private void RenderDiagram(Path diagramPath, ExtensionHtmlRenderer renderer)
        {
            var  folder = _renderSettings.ImageFolder;
            File file   = _provider.GetDiagramFile(diagramPath, folder);

            if (IO.File.Exists(file.AbsolutePath))
            {
                if (_renderSettings.EmbedImages)
                {
                    var bytes  = IO.File.ReadAllBytes(file.AbsolutePath);
                    var base64 = Convert.ToBase64String(bytes);
                    renderer.Write($@"<img src='data:image/png;base64,{base64}' />");
                }
                else
                {
                    renderer.Write($@"<img src='{file.RelativePath}' />");
                }
            }
            else
            {
                renderer.Write($@"<p>something went wrong retrieving the image [{diagramPath}]</p>");
            }
        }