/// <summary>
        /// Cancels a pending payment.
        /// </summary>
        /// <param name="id">Payment id.</param>
        /// <param name="requestOptions"><see cref="RequestOptions"/>.</param>
        /// <returns>The cancelled payment.</returns>
        /// <exception cref="MercadoPagoException">If a unexpected exception occurs.</exception>
        /// <exception cref="MercadoPagoApiException">If the API returns a error.</exception>
        public Resource.Payment.Payment Cancel(
            long id,
            RequestOptions requestOptions = null)
        {
            var request = new PaymentCancelRequest();

            return(Send(
                       $"/v1/payments/{id}",
                       HttpMethod.Put,
                       request,
                       requestOptions));
        }
        /// <summary>
        /// Cancels a pending payment async.
        /// </summary>
        /// <param name="id">Payment id.</param>
        /// <param name="requestOptions"><see cref="RequestOptions"/>.</param>
        /// <param name="cancellationToken">Cancellation token.</param>
        /// <returns>A task whose the result is the cancelled payment.</returns>
        /// <exception cref="MercadoPagoException">If a unexpected exception occurs.</exception>
        /// <exception cref="MercadoPagoApiException">If the API returns a error.</exception>
        public Task <Resource.Payment.Payment> CancelAsync(
            long id,
            RequestOptions requestOptions       = null,
            CancellationToken cancellationToken = default)
        {
            var request = new PaymentCancelRequest();

            return(SendAsync(
                       $"/v1/payments/{id}",
                       HttpMethod.Put,
                       request,
                       requestOptions,
                       cancellationToken));
        }