/// <summary>
        /// Adds the button to the notification message.
        /// </summary>
        /// <param name="builder">The builder.</param>
        /// <param name="content">The content.</param>
        /// <param name="callback">The callback.</param>
        /// <returns>Returns the notification message builder.</returns>
        public static NotificationMessageBuilder WithButton(
            this NotificationMessageBuilder builder,
            object content,
            Action <INotificationMessageButton> callback)
        {
            var button = builder.Manager.Factory.GetButton();

            button.Callback = callback;
            button.Content  = content;

            builder.AddButton(button);

            return(builder);
        }