public static bool Contains <TSource>(this ImmutableList <TSource> source, TSource value, IEqualityComparer <TSource>?comparer = default) => ReadOnlyListExtensions.Contains <ValueWrapper <TSource>, TSource>(new ValueWrapper <TSource>(source), value, comparer);
public static bool Contains <TSource>(this ImmutableArray <TSource> source, [AllowNull] TSource value, IEqualityComparer <TSource>?comparer) => ReadOnlyListExtensions.Contains <ImmutableArray <TSource>, TSource>(source, value, comparer);