public void Ok()
        {
            var d = new MyStruct();

            Action act = () =>
            {
                d.Dispose();
                d.Dispose();
            };

            act.Should().Throw <ObjectDisposedException>();
        }
        public void StillOk()
        {
            Action act = () =>
            {
                using (var d = new MyStruct())
                {
                    d.Dispose();
                }
            };

            act.Should().Throw <ObjectDisposedException>();
        }
        public void Suddenly()
        {
            Action act = () =>
            {
                var d = new MyStruct();
                using (d)
                {
                    d.Dispose();
                }
            };

            act.Should().Throw <Exception>();
        }