/// <summary>
        /// Get metered license consumption
        /// </summary>
        public static void GetMeteredLicenseConsumption()
        {
            //ExStart:GetMeteredLicenseConsumption
            // Create new instance of GroupDocs.Viewer.Metered class
            GroupDocs.Viewer.Metered metered = new GroupDocs.Viewer.Metered();

            // Set public and private keys
            string publicKey  = "***";
            string privateKey = "***";

            // Set public and private keys to metered instance
            metered.SetMeteredKey(publicKey, privateKey);

            // Get pages
            GroupDocs.Viewer.Handler.ViewerHtmlHandler   htmlHandler = new GroupDocs.Viewer.Handler.ViewerHtmlHandler();
            List <GroupDocs.Viewer.Domain.Html.PageHtml> pages       = htmlHandler.GetPages("input.pdf");

            // Get metered consumption quantity after usage of the comparison
            decimal amountAfter = GroupDocs.Viewer.Metered.GetConsumptionQuantity();

            Console.WriteLine("Amount (MB) consumed: " + amountAfter);

            // Get metered consumption credit (Since version 19.6)
            decimal creditAfter = GroupDocs.Viewer.Metered.GetConsumptionCredit();
            //ExEnd:GetMeteredLicenseConsumption
        }
        /// <summary>
        /// Set metered license
        /// </summary>
        public static void ApplyMeteredLicense()
        {
            //ExStart:ApplyMeteredLicense
            // Create new instance of GroupDocs.Viewer.Metered class
            GroupDocs.Viewer.Metered metered = new GroupDocs.Viewer.Metered();

            // Set public and private keys
            string publicKey  = "***";
            string privateKey = "***";

            // Set public and private keys to metered instance
            metered.SetMeteredKey(publicKey, privateKey);
            //ExEnd:ApplyMeteredLicense
        }