Braintree\Util::_removeWildcardKeys PHP Method

    private static function _removeWildcardKeys($validKeys, $invalidKeys)
    {
        foreach ($validKeys as $key) {
            if (stristr($key, '[_anyKey_]')) {
                $wildcardKey = str_replace('[_anyKey_]', '', $key);
                foreach ($invalidKeys as $index => $invalidKey) {
                    if (stristr($invalidKey, $wildcardKey)) {
                        unset($invalidKeys[$index]);
                    }
                }
            }
        }
        return $invalidKeys;
    }