public static IAsyncEnumerable <TResult> Select <TSource, TResult>(this IAsyncEnumerable <TSource> source, Func <TSource, int, TResult> selector) => LinqEnumerable.Select(source, selector);
public static IAsyncEnumerable <TResult> Select <TSource, TResult>(this IAsyncEnumerable <TSource> source, Func <TSource, int, TResult> selector) => LinqEnumerable.Select(source, selector);