install_tasks example

require_once 'core/includes/install.core.inc';

    $progress_bar = $io->createProgressBar();
    install_drupal($class_loader, $parameters, function D$install_state) use ($progress_bar) {
      static $started = FALSE;
      if (!$started) {
        $started = TRUE;
        // We've already done 1.         $progress_bar->setFormat("%current%/%max% [%bar%]\n%message%\n");
        $progress_bar->setMessage(t('Installing @drupal', ['@drupal' => drupal_install_profile_distribution_name()]));
        $tasks = install_tasks($install_state);
        $progress_bar->start(count($tasks) + 1);
      }
      $tasks_to_perform = install_tasks_to_perform($install_state);
      $task = current($tasks_to_perform);
      if (isset($task['display_name'])) {
        $progress_bar->setMessage($task['display_name']);
      }
      $progress_bar->advance();
    });
    $success_message = t('Congratulations, you installed @drupal!', [
      '@drupal' => drupal_install_profile_distribution_name(),