void IDisposable.Dispose()
            {
                if (_pool != null)
                {
                    if (!_pool.Return(Client))
                    {
                        Client.Dispose();
                    }

                    _pool  = null;
                    Client = null;
                }
            }
            public Lease(CdsServiceClientPool pool)
            {
                _pool = pool;

                Client = _pool.Rent();
            }