Barryvdh\Cors\Stack\CorsService::normalizeOptions PHP Method

    private function normalizeOptions(array $options = array())
    {
        $options += array('allowedOrigins' => array(), 'supportsCredentials' => false, 'allowedHeaders' => array(), 'exposedHeaders' => array(), 'allowedMethods' => array(), 'maxAge' => 0);
        // normalize array('*') to true
        if (in_array('*', $options['allowedOrigins'])) {
            $options['allowedOrigins'] = true;
        }
        if (in_array('*', $options['allowedHeaders'])) {
            $options['allowedHeaders'] = true;
        } else {
            $options['allowedHeaders'] = array_map('strtolower', $options['allowedHeaders']);
        }
        if (in_array('*', $options['allowedMethods'])) {
            $options['allowedMethods'] = true;
        } else {
            $options['allowedMethods'] = array_map('strtoupper', $options['allowedMethods']);
        }
        return $options;
    }