We can reproduce it by setting up -https://www.drupal.org/docs/7/modules/api-...

We can reproduce it by setting up -
https://www.drupal.org/docs/7/modules/api-module/create-your-own-api-7x-...

and then checking the documentation page for Attributes.php.

The issue is also visible here: https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Template%...

Also, just a thought - phpcs does not even give a warning for this, should this also be included in Drupal coding standards?