Platformsh\Cli\Util\ActivityUtil::waitMultiple PHP Method

    public static function waitMultiple(array $activities, OutputInterface $output, Project $project)
    {
        $count = count($activities);
        if ($count == 0) {
            return true;
        } elseif ($count === 1) {
            return self::waitAndLog(reset($activities), $output);
        }
        $output->writeln("Waiting for {$count} activities...");
        // Initialize a progress bar which will show elapsed time and all of the
        // activities' states.
        $bar = new ProgressBar($output);
        $states = [];
        foreach ($activities as $activity) {
            $state = $activity->state;
            $states[$state] = isset($states[$state]) ? $states[$state] + 1 : 1;
        }
        $bar->setPlaceholderFormatterDefinition('states', function () use(&$states) {
            $format = '';
            foreach ($states as $state => $count) {
                $format .= $count . ' ' . self::formatState($state) . ', ';
            }
            return rtrim($format, ', ');
        });
        $bar->setFormat("  [%bar%] %elapsed:6s% (%states%)");
        $bar->start();
        // Get the most recent created date of each of the activities, as a Unix
        // timestamp, so that they can be more efficiently refreshed.
        $mostRecentTimestamp = 0;
        foreach ($activities as $activity) {
            $created = strtotime($activity->created_at);
            $mostRecentTimestamp = $created > $mostRecentTimestamp ? $created : $mostRecentTimestamp;
        }
        // Wait for the activities to complete, polling (refreshing) all of them
        // with a 1 second delay.
        $complete = 0;
        while ($complete < $count) {
            sleep(1);
            $states = [];
            $complete = 0;
            // Get a list of activities on the project. Any of our activities
            // which are not contained in this list must be refreshed
            // individually.
            $projectActivities = $project->getActivities(0, null, $mostRecentTimestamp ?: null);
            foreach ($activities as $activity) {
                $refreshed = false;
                foreach ($projectActivities as $projectActivity) {
                    if ($projectActivity->id === $activity->id) {
                        $activity = $projectActivity;
                        $refreshed = true;
                        break;
                    }
                }
                if (!$refreshed && !$activity->isComplete()) {
                    $activity->refresh();
                }
                if ($activity->isComplete()) {
                    $complete++;
                }
                $state = $activity->state;
                $states[$state] = isset($states[$state]) ? $states[$state] + 1 : 1;
            }
            $bar->advance();
        }
        $bar->finish();
        $output->writeln('');
        // Display success or failure messages for each activity.
        $success = true;
        foreach ($activities as $activity) {
            $description = $activity->getDescription();
            switch ($activity['result']) {
                case Activity::RESULT_SUCCESS:
                    $output->writeln("Activity <info>{$activity->id}</info> succeeded: {$description}");
                    break;
                case Activity::RESULT_FAILURE:
                    $success = false;
                    $output->writeln("Activity <error>{$activity->id}</error> failed");
                    // If the activity failed, show the complete log.
                    $output->writeln("  Description: {$description}");
                    $output->writeln("  Log:");
                    $output->writeln(preg_replace('/^/m', '    ', $activity->log));
                    break;
            }
        }
        return $success;
    }

 /**
  * {@inheritdoc}
  */
 protected function execute(InputInterface $input, OutputInterface $output)
 {
     $this->validateInput($input);
     if (!$this->validateDomainInput($input)) {
         return 1;
     }
     $project = $this->getSelectedProject();
     try {
         $this->stdErr->writeln("Adding the domain <info>{$this->domainName}</info>");
         $result = $project->addDomain($this->domainName, $this->sslOptions);
     } catch (ClientException $e) {
         // Catch 409 Conflict errors.
         $response = $e->getResponse();
         if ($response && $response->getStatusCode() === 409) {
             $this->stdErr->writeln("The domain <error>{$this->domainName}</error> already exists on the project.");
             $this->stdErr->writeln("Use <info>domain:delete</info> to delete an existing domain");
         } else {
             $this->handleApiException($e, $project);
         }
         return 1;
     }
     if (!$input->getOption('no-wait')) {
         ActivityUtil::waitMultiple($result->getActivities(), $this->stdErr);
     }
     return 0;
 }