Omnipay\Common\CreditCard::getBillingState PHP Method

    public function getBillingState()
    {
        return $this->getParameter('billingState');
    }

 public function testState()
 {
     $this->card->setState('RI');
     $this->assertEquals('RI', $this->card->getState());
     $this->assertEquals('RI', $this->card->getBillingState());
     $this->assertEquals('RI', $this->card->getShippingState());
 }