phpbb\user_loader::get_user PHP Method

    public function get_user($user_id, $query = false)
    {
        if (isset($this->users[$user_id])) {
            return $this->users[$user_id];
        } else {
            if ($query || $user_id == ANONYMOUS) {
                $this->load_users(array($user_id));
                return $this->get_user($user_id);
            }
        }
        return $this->get_user(ANONYMOUS);
    }

 /**
  * Notify using phpBB messenger
  *
  * @param int $notify_method				Notify method for messenger (e.g. NOTIFY_IM)
  * @param string $template_dir_prefix	Base directory to prepend to the email template name
  *
  * @return null
  */
 protected function notify_using_messenger($notify_method, $template_dir_prefix = '')
 {
     if (empty($this->queue)) {
         return;
     }
     // Load all users we want to notify (we need their email address)
     $user_ids = $users = array();
     foreach ($this->queue as $notification) {
         $user_ids[] = $notification->user_id;
     }
     // We do not send emails to banned users
     if (!function_exists('phpbb_get_banned_user_ids')) {
         include $this->phpbb_root_path . 'includes/functions_user.' . $this->php_ext;
     }
     $banned_users = phpbb_get_banned_user_ids($user_ids);
     // Load all the users we need
     $this->user_loader->load_users($user_ids);
     // Load the messenger
     if (!class_exists('messenger')) {
         include $this->phpbb_root_path . 'includes/functions_messenger.' . $this->php_ext;
     }
     $messenger = new \messenger();
     // Time to go through the queue and send emails
     /** @var \phpbb\notification\type\type_interface $notification */
     foreach ($this->queue as $notification) {
         if ($notification->get_email_template() === false) {
             continue;
         }
         $user = $this->user_loader->get_user($notification->user_id);
         if ($user['user_type'] == USER_IGNORE || $user['user_type'] == USER_INACTIVE && $user['user_inactive_reason'] == INACTIVE_MANUAL || in_array($notification->user_id, $banned_users)) {
             continue;
         }
         $messenger->template($notification->get_email_template(), $user['user_lang'], '', $template_dir_prefix);
         $messenger->set_addresses($user);
         $messenger->assign_vars(array_merge(array('USERNAME' => $user['username'], 'U_NOTIFICATION_SETTINGS' => generate_board_url() . '/ucp.' . $this->php_ext . '?i=ucp_notifications&mode=notification_options'), $notification->get_email_template_variables()));
         $messenger->send($notify_method);
     }
     // Save the queue in the messenger class (has to be called or these emails could be lost?)
     $messenger->save_queue();
     // We're done, empty the queue
     $this->empty_queue();
 }