example usage of AggregateUntil() with Google's AdWords API

AggregateUntilAdWordsExample.cs

private static List<CriterionBidLandscape> GetCriterionBidLandscapes(DataService dataService, string awql)
{
    var bidLandscapes = Enumerable
	.Range(0, Int32.MaxValue)
	.AggregateUntil(
	    new CriterionBidLandscapePage()
	    {
		entries = new CriterionBidLandscape[] { },
		totalNumEntries = 0,
	    },
	    (accumulatedCriterionBidLandscapePage, pageIndex) =>
	    {
		var awqlLimited = $"{awql} LIMIT {pageIndex * pageSize},{pageSize}";

		var theseKeywordsPage = Enumerable
		    .Range(0, pageMaxFetchAttempts)
		    .Select(pageAttempt =>
		    {
			Thread.Sleep(2500 * pageAttempt * pageAttempt);
			try
			{
			    var page = dataService.queryCriterionBidLandscape(awqlLimited);
			    return page;
			}
			catch (AdWordsApiException e)
			{
			    return null;
			}
		    })
		    .First(page => page != null); //TODO: catch the error that this could throw

		return new CriterionBidLandscapePage()
		{
		    entries = accumulatedCriterionBidLandscapePage
			.entries
			.ToList()
			.Concat(theseKeywordsPage.entries)
			.ToArray(),
		    totalNumEntries = theseKeywordsPage.totalNumEntries,
		    totalNumEntriesSpecified = theseKeywordsPage.totalNumEntriesSpecified,
		    PageType = theseKeywordsPage.PageType,
		};
	    },
	    (accumulatedKeywordPage) =>
	    {
		var shouldStop = accumulatedKeywordPage.entries.Length >= accumulatedKeywordPage.totalNumEntries;
		return shouldStop;
	    })
	.entries
	.ToList();

    return bidLandscapes;
}