presto-8.x-2.2/modules/presto_commerce/presto_commerce.module

<?php

/**
 * @file
 * Contains presto_commerce.module.
 */

use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function presto_commerce_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the presto_commerce module.
    case 'help.page.presto_commerce':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Provides some sane configuration defaults for Drupal Commerce.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements theme_hook().
 */
function presto_commerce_theme($existing, $type, $theme, $path) {
  return [
    'commerce_checkout_completion_message' => [
      'template' => 'commerce-checkout-completion-message',
      'base hook' => 'commerce_checkout_completion_message',
    ],
  ];
}