/**
  * Open Invoice NL is not available if quote has a coupon
  *
  * @param Mage_Sales_Model_Quote $quote
  * @return boolean
  */
 public function isAvailable($quote = null)
 {
     /* availability depends on quote */
     if (false == $quote instanceof Mage_Sales_Model_Quote) {
         return false;
     }
     /* not available if there is no gender or no birthday */
     if (is_null($quote->getCustomerGender()) || is_null($quote->getCustomerDob())) {
         return false;
     }
     return parent::isAvailable($quote);
 }
 /**
  * Open Invoice DE is not available if quote has a coupon
  *
  * @param Mage_Sales_Model_Quote $quote
  * @return boolean
  */
 public function isAvailable($quote = null)
 {
     /* availability depends on quote */
     if (false == $quote instanceof Mage_Sales_Model_Quote) {
         return false;
     }
     /* not available if quote contains a coupon and allow_discounted_carts is disabled */
     if (!$this->isAvailableForDiscountedCarts() && $quote->getSubtotal() != $quote->getSubtotalWithDiscount()) {
         return false;
     }
     /* not available if there is no gender or no birthday */
     if (is_null($quote->getCustomerGender()) || is_null($quote->getCustomerDob())) {
         return false;
     }
     return parent::isAvailable($quote);
 }