gistfile1.php

    /**
     * Load available payment methods for an order.
     *
     * @param string $order_uuid
     *   The order's UUID.
     *
     * @return array
     *   The available payment methods.
     */
    public function getUserPaymentMethods($order_uuid)
    {
        static $options = array();

        if (empty($options)) {
            // Bootstrap store.
            $this->drupalWithUser->bootstrapStore();

            // Load the order.
            $order = reset(entity_uuid_load('commerce_order', array($order_uuid)));

            rules_invoke_all('commerce_payment_methods', $order);
            drupal_alter('commerce_payment_methods', $order);

            // Sort the payment methods array by the enabling Rules' weight values.
            uasort($order->payment_methods, 'drupal_sort_weight');

            // Generate an array of payment method options for the checkout form.
            $options = array();

            foreach ($order->payment_methods as $instance_id => $method_info) {
                // Ensure we've received a valid payment method that can be used on the
                // checkout form.
                if ($payment_method = commerce_payment_method_load($method_info['method_id'])) {
                    if (!empty($payment_method['checkout'])) {
                        $options[$instance_id] = $payment_method['display_title'];
                    }
                }
            }
        }

        return $options;
    }