wp-includes/SimplePie/src/Enclosure.php:461Get the file extension
string|null public function get_extension() { if ($this->link !== null) { $url = \SimplePie\Misc::parse_url($this->link); if ($url['path'] !== '') { return pathinfo($url['path'], PATHINFO_EXTENSION); } } return null; }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/SimplePie/src/Enclosure.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.