public static ValueTask <bool> ContainsAsync <TSource>(this IAsyncEnumerable <TSource> source, TSource value, IEqualityComparer <TSource> comparer) => LinqEnumerable.ContainsAsync(source, value, comparer);
public static ValueTask <bool> ContainsAsync <TSource>(this IAsyncEnumerable <TSource> source, TSource value) => LinqEnumerable.ContainsAsync(source, value);