NSDataStream.cs

        public unsafe class NSDataStream : UnmanagedMemoryStream
        {
                public NSDataStream(NSData data)
                        : base((byte*)data.Bytes, data.Length)
                {
                        _data = data;
                }

                private readonly NSData _data;

                protected override void Dispose(bool disposing)
                {
                        if (disposing)
                                _data.Dispose();

                        base.Dispose(disposing);
                }
        }