/// <summary>
        ///   <para>Visual color scheme of button.</para>
        /// </summary>
        /// <param name="widget">Widget to call method on.</param>
        /// <param name="scheme">Color scheme for button.</param>
        /// <returns>Reference to provided <paramref name="widget"/>.</returns>
        /// <exception cref="ArgumentNullException">If <paramref name="widget"/> is a <c>null</c> reference.</exception>
        /// <seealso cref="ITumblrFollowButtonWidget.ColorScheme(string)"/>
        public static ITumblrFollowButtonWidget ColorScheme(this ITumblrFollowButtonWidget widget, TumblrFollowButtonColorScheme scheme)
        {
            Assertion.NotNull(widget);

            return(widget.ColorScheme(scheme.ToString().ToLowerInvariant()));
        }
        /// <summary>
        ///   <para>Visual layout/appearance of button.</para>
        /// </summary>
        /// <param name="widget">Widget to call method on.</param>
        /// <param name="type">Layout of button.</param>
        /// <returns>Reference to provided <paramref name="widget"/>.</returns>
        /// <exception cref="ArgumentNullException">If <paramref name="widget"/> is a <c>null</c> reference.</exception>
        /// <seealso cref="ITumblrFollowButtonWidget.Type(byte)"/>
        public static ITumblrFollowButtonWidget Type(this ITumblrFollowButtonWidget widget, TumblrFollowButtonType type)
        {
            Assertion.NotNull(widget);

            return(widget.Type((byte)type));
        }