wp-includes/SimplePie/src/Enclosure.php:428Get the duration of the enclosure
$convertbooloptionalfalsestring|int|null public function get_duration($convert = false) { if ($this->duration !== null) { if ($convert) { $time = \SimplePie\Misc::time_hms($this->duration); return $time; } return $this->duration; } 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.