public static ValueTask <TSource> SingleOrDefaultAsync <TSource>(this IAsyncEnumerable <TSource> source, Func <TSource, bool> predicate) => LinqEnumerable.SingleOrDefaultAsync(source, predicate);
public static ValueTask <TSource> SingleOrDefaultAsync <TSource>(this IAsyncEnumerable <TSource> source) => LinqEnumerable.SingleOrDefaultAsync(source);