/// <summary>
        /// Appends a HTML-encoded string representing this instance to the <paramref name="stringBuilder"/> containing the Twitter card meta tags.
        /// </summary>
        /// <param name="stringBuilder">The string builder.</param>
        public override void ToString(StringBuilder stringBuilder)
        {
            base.ToString(stringBuilder);

            stringBuilder.AppendMetaNameContentIfNotNull("twitter:title", this.Title);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:description", this.Description);
            if (this.Image != null)
            {
                stringBuilder.AppendMetaNameContent("twitter:image", this.Image.ImageUrl);
                stringBuilder.AppendMetaNameContentIfNotNull("twitter:image:height", this.Image.Height);
                stringBuilder.AppendMetaNameContentIfNotNull("twitter:image:width", this.Image.Width);
            }
        }
        /// <summary>
        /// Appends a HTML-encoded string representing this instance to the <paramref name="stringBuilder"/> containing the Twitter card meta tags.
        /// </summary>
        /// <param name="stringBuilder">The string builder.</param>
        public override void ToString(StringBuilder stringBuilder)
        {
            base.ToString(stringBuilder);

            stringBuilder.AppendMetaNameContentIfNotNull("twitter:description", this.Description);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:id:iphone", this.IPhone);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:url:iphone", this.IPhoneCustomUrlScheme);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:id:ipad", this.IPad);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:url:ipad", this.IPadCustomUrlScheme);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:id:googleplay", this.GooglePlay);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:url:googleplay", this.GooglePlayCustomUrlScheme);
            stringBuilder.AppendMetaNameContentIfNotNull("twitter:app:country", this.Country);
        }