Omnipay\Common\CreditCard::setFax PHP Method

    public function setFax($value)
    {
        $this->setParameter('billingFax', $value);
        $this->setParameter('shippingFax', $value);
        return $this;
    }

 public function testFax()
 {
     $this->card->setFax('54321');
     $this->assertEquals('54321', $this->card->getFax());
     $this->assertEquals('54321', $this->card->getBillingFax());
     $this->assertEquals('54321', $this->card->getShippingFax());
 }