the code below is not about laziness. IEqualityComparer), Last(IEnumerable, Func), LastOrDefault(IEnumerable), LastOrDefault(IEnumerable, TSource), LastOrDefault(IEnumerable, Func), LastOrDefault(IEnumerable, Func, TSource), LongCount(IEnumerable, Func), Max(IEnumerable, IComparer), Max(IEnumerable, Func), Max(IEnumerable, Func), Max(IEnumerable, Func), Max(IEnumerable, Func), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func), Max(IEnumerable, Func), MaxBy(IEnumerable, Func), MaxBy(IEnumerable, Func, IComparer), Min(IEnumerable, IComparer), Min(IEnumerable, Func), Min(IEnumerable, Func), Min(IEnumerable, Func), Min(IEnumerable, Func), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func), Min(IEnumerable, Func), MinBy(IEnumerable, Func), MinBy(IEnumerable, Func, IComparer), OrderBy(IEnumerable, Func), OrderBy(IEnumerable, Func, IComparer), OrderByDescending(IEnumerable, Func), OrderByDescending(IEnumerable, Func, IComparer), OrderDescending(IEnumerable, IComparer), Prepend(IEnumerable, TSource), Select(IEnumerable, Func), Select(IEnumerable, Func), SelectMany(IEnumerable, Func>), SelectMany(IEnumerable, Func>), SelectMany(IEnumerable, Func>, Func), SelectMany(IEnumerable, Func>, Func), SequenceEqual(IEnumerable, IEnumerable), SequenceEqual(IEnumerable, IEnumerable, IEqualityComparer), Single(IEnumerable, Func), SingleOrDefault(IEnumerable), SingleOrDefault(IEnumerable, TSource), SingleOrDefault(IEnumerable, Func), SingleOrDefault(IEnumerable, Func, TSource), Skip(IEnumerable, Int32), SkipLast(IEnumerable, Int32), SkipWhile(IEnumerable, Func), SkipWhile(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func), Take(IEnumerable, Int32), Take(IEnumerable, Range), TakeLast(IEnumerable, Int32), TakeWhile(IEnumerable, Func), TakeWhile(IEnumerable, Func), ToDictionary(IEnumerable, Func), ToDictionary(IEnumerable, Func, IEqualityComparer), ToDictionary(IEnumerable, Func, Func), ToDictionary(IEnumerable, Func, Func, IEqualityComparer), ToHashSet(IEnumerable, IEqualityComparer), ToLookup(IEnumerable, Func), ToLookup(IEnumerable, Func, IEqualityComparer), ToLookup(IEnumerable, Func, Func), ToLookup(IEnumerable