src/Common/CreditCard.php
public function addSupportedBrand($name, $expression)
    {
        $known_brands = array_keys($this->supported_cards);

        if (in_array($name, $known_brands)) {
            return false;
        }

        $this->supported_cards[$name] = $expression;
        return true;
    }
public function addSupportedBrand($name, $expression)
    {
        $known_brands = array_keys($this->supported_cards);

        if (in_array($name, $known_brands)) {
            return false;
        }

        $this->supported_cards[$name] = $expression;
        return true;
    }
Set a custom supported card brand with a regular expression to match it.

Note: The fact that a particular card is known does not imply that your
gateway supports it.

Set $add_to_front to true if the key should be added to the front of the array

@param  string  $name The name of the new supported brand.
@param  string  $expression The regular expression to check if a card is supported.
@return boolean success