Timber\ImageHelper::_delete_generated_if_image PHP Method

    public static function _delete_generated_if_image($post_id)
    {
        if (wp_attachment_is_image($post_id)) {
            $attachment = new Image($post_id);
            if ($attachment->file_loc) {
                ImageHelper::delete_generated_files($attachment->file_loc);
            }
        }
    }

 /**
  * Deletes all resized versions of an image when the source is deleted
  * or its meta data is regenerated
  */
 protected static function add_actions()
 {
     add_action('delete_attachment', function ($post_id) {
         \Timber\ImageHelper::_delete_generated_if_image($post_id);
     });
     add_filter('wp_generate_attachment_metadata', function ($metadata, $post_id) {
         \Timber\ImageHelper::_delete_generated_if_image($post_id);
         return $metadata;
     }, 10, 2);
 }