namespace System.Collections.Immutable
{
    [DefaultMember("Item")]
    public struct ImmutableArray<T> : ICollection<T>, IEnumerable, IEnumerable<T>, IList<T>, IReadOnlyCollection<T>, IReadOnlyList<T>, ICollection, IList, IImmutableList<T>, IStructuralComparable, IStructuralEquatable, IEquatable<ImmutableArray<T>>
    {
        public int LastIndexOf(T item, int startIndex, int count, IEqualityComparer<T> equalityComparer);
    }
}