private async Task CreateMenuAsync(string menuName, System.Drawing.Image image, params ActionArea[] areas)
        {
            var menu = new RichMenu()
            {
                Name        = menuName,
                ChatBarText = CHAT_BAR_TEXT,
                Selected    = true,
                Size        = ImagemapSize.RichMenuShort,
                Areas       = areas
            };
            var menuId = await _client.CreateRichMenuAsync(menu);

            using (var stream = new System.IO.MemoryStream())
            {
                image.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
                stream.Position = 0;
                await _client.UploadRichMenuPngImageAsync(stream, menuId);
            }
        }