139         static U Iterate<T, U>(IEnumerable<T> source, U initValue, Func<T, U, U> selector) {  in Iterate()  argument
142                 initValue = selector(element, initValue);  in Iterate()
166 …e<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) {  in Select()  argument
167             Check.SourceAndSelector(source, selector);  in Select()
169             return CreateSelectIterator(source, selector);  in Select()
172 …ateSelectIterator<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) {  in CreateSelectIterator()  argument
174                 yield return selector(element);  in CreateSelectIterator()
177 …sult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, int, TResult> selector) {  in Select()  argument
178             Check.SourceAndSelector(source, selector);  in Select()
180             return CreateSelectIterator(source, selector);  in Select()
183 …lectIterator<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, int, TResult> selector) {  in CreateSelectIterator()  argument
186                 yield return selector(element, counter);  in CreateSelectIterator()
196 … int, IEnumerable<TCollection>> collectionSelector, Func<TSource, TCollection, TResult> selector) {  in SelectMany()  argument
197             Check.SourceAndCollectionSelectors(source, collectionSelector, selector);  in SelectMany()
199             return CreateSelectManyIterator(source, collectionSelector, selector);  in SelectMany()
202 …TSource, TResult>(IEnumerable<TSource> source, Func<TSource, int, IEnumerable<TResult>> selector) {  in SelectMany()  argument
203             Check.SourceAndSelector(source, selector);  in SelectMany()
205             return CreateSelectManyIterator(source, selector);  in SelectMany()
209 … int, IEnumerable<TCollection>> collectionSelector, Func<TSource, TCollection, TResult> selector) {  in CreateSelectManyIterator()  argument
213                     yield return selector(element, collection);  in CreateSelectManyIterator()
216 …TSource, TResult>(IEnumerable<TSource> source, Func<TSource, int, IEnumerable<TResult>> selector) {  in CreateSelectManyIterator()  argument
219                 foreach (TResult item in selector(element, counter))  in CreateSelectManyIterator()
235         static TR Sum<TA, TR>(IEnumerable<TA> source, Func<TR, TA, TR> selector) {  in Sum()  argument
238                 total = selector(total, element);  in Sum()