public function isAvailable($quote = null)
 {
     $currency_code = $this->getQuote()->getQuoteCurrencyCode();
     if (!empty($currency_code) && $currency_code != 'TRY') {
         return false;
     }
     return parent::isAvailable($quote);
 }
 public function isAvailable($quote = null)
 {
     $billing = $this->getQuote()->getBillingAddress();
     $shipping = $this->getQuote()->getShippingAddress();
     if ($billing->getFirstname() != $shipping->getFirstname() or $billing->getLastname() != $shipping->getLastname() or $billing->getStreet() != $shipping->getStreet() or $billing->getPostcode() != $shipping->getPostcode() or $billing->getCity() != $shipping->getCity() or $billing->getCountry() != $shipping->getCountry()) {
         return false;
     }
     return parent::isAvailable($quote);
 }