acf gallery images resolver

acf-gallery.php

add_filter('graphql_post_fields', function($fields) {
    $fields['post_images'] = [
        'type' => \WPGraphQL\Types::list_of(\WPGraphQL\Types::post_object('attachment')),
        'description' => __('Images on posts', 'mostly plants'),
        'resolve' => function(\WP_Post $post) {
      $post_images = get_field('post_images', $post->ID);
      $images = [];
      if (!empty($post_images) && is_array($post_images)) {
        for ($i = 0; $i < count($post_images); $i++) {
           $images[] = \WPGraphQL\Data\DataSource::resolve_post_object($post_images[$i]['ID'], 'attachment');
        }
      }
      return $images;
        },
    ];
    return $fields;
});