wp-includes/sitemaps/class-wp-sitemaps-provider.php:179array public function get_object_subtypes() { return array(); }Introduced in 5.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/sitemaps/class-wp-sitemaps-provider.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.