public function redeemCoupon($accountCode, $currency)
 {
     $redemption = new Recurly_CouponRedemption();
     $redemption->account_code = $accountCode;
     $redemption->currency = $currency;
     foreach ($this->_links as $link) {
         if ($link->name == 'redeem') {
             $redemption->_save(strtoupper($link->method), $link->href);
             return $redemption;
         }
     }
 }
 public function redeemCoupon($accountCode, $currency)
 {
     if ($this->state != 'redeemable') {
         throw new Recurly_Error('Coupon is not redeemable.');
     }
     $redemption = new Recurly_CouponRedemption(null, $this->_client);
     $redemption->account_code = $accountCode;
     $redemption->currency = $currency;
     foreach ($this->_links as $link) {
         if ($link->name == 'redeem') {
             $redemption->_save(strtoupper($link->method), $link->href);
             return $redemption;
         }
     }
 }