Stripe\SubscriptionTest::testDeleteDiscount PHP Метод

    public function testDeleteDiscount()
    {
        $planID = 'gold-' . self::generateRandomString(20);
        self::retrieveOrCreatePlan($planID);
        $couponID = '25off-' . self::generateRandomString(20);
        self::retrieveOrCreateCoupon($couponID);
        $customer = self::createTestCustomer();
        $sub = $customer->subscriptions->create(array('plan' => $planID, 'coupon' => $couponID));
        $this->assertSame($sub->status, 'active');
        $this->assertSame($sub->plan->id, $planID);
        $this->assertSame($sub->discount->coupon->id, $couponID);
        $sub->deleteDiscount();
        $sub = $customer->subscriptions->retrieve($sub->id);
        $this->assertNull($sub->discount);
    }