public RestResponse <PageTrackingResponse> GetPageTracking(string profileID, string relativeUrl, DateTime?startDate = null, DateTime?endDate = null)
        {
            RestRequest request = new RestRequest(GoogleConstants.GoogleAnalyticsUrl, RequestMode.UrlEncoded, AcceptMode.Json);


            request.Parameters.Add("ids", "ga:" + profileID);
            request.Parameters.Add("start-date", startDate.HasValue ? startDate.Value.ToString("yyyy-MM-dd") : "30daysAgo");
            request.Parameters.Add("end-date", endDate.HasValue ? endDate.Value.ToString("yyyy-MM-dd") : "today");
            request.Parameters.Add("metrics", new[] { MetricesType.UniquePageViews, MetricesType.PageValue,
                                                      MetricesType.Entrances, MetricesType.PageViews, MetricesType.TimeOnPage,
                                                      MetricesType.Exits, MetricesType.EntranceRate, MetricesType.PageViewsPerVisit,
                                                      MetricesType.AverageTimeOnPage, MetricesType.ExitRate }.Select(x => x.ToDescription()).ToConcatenatedString(","));
            request.Parameters.Add("filters", "ga:pagePath=~" + UrlPath.AppendLeadingSlash(relativeUrl));

            return(this.Get <PageTrackingResponse>(request));
        }