public static ValueReadOnlyCollectionExtensions.SelectAtEnumerable <ValueWrapper <TSource>, ImmutableHashSet <TSource> .Enumerator, TSource, TResult, TSelector> SelectAt <TSource, TResult, TSelector>(
this ImmutableHashSet <TSource> source,
TSelector selector = default)
where TSelector : struct, IFunction <TSource, int, TResult>
=> ValueReadOnlyCollectionExtensions.SelectAt <ValueWrapper <TSource>, ImmutableHashSet <TSource> .Enumerator, TSource, TResult, TSelector>(new ValueWrapper <TSource>(source), selector);
