Expanded class hierarchy of TestHtmlMailCollector in Drupal 10
- class \Drupal\Core\Mail\Plugin\Mail\PhpMail implements MailInterface
- class \Drupal\Core\Mail\Plugin\Mail\TestMailCollector implements MailInterface
- class \Drupal\mail_html_test\Plugin\Mail\TestHtmlMailCollector
- class \Drupal\system_mail_failure_test\Plugin\Mail\TestPhpMailFailure implements MailInterface
- class \Drupal\Core\Mail\Plugin\Mail\TestMailCollector implements MailInterface