WellCommerce\Bundle\CouponBundle\Entity\Coupon::setCurrency PHP Method

    public function setCurrency(string $currency)
    {
        $this->currency = $currency;
    }

 public function create() : CouponInterface
 {
     $coupon = new Coupon();
     $coupon->setClientUsageLimit(1);
     $coupon->setGlobalUsageLimit(1);
     $coupon->setModifierType('%');
     $coupon->setModifierValue(100);
     $coupon->setCode(strtoupper(uniqid()));
     $coupon->setCurrency('');
     return $coupon;
 }