wp-includes/Text/Diff.php:342 function nfinal() { return $this->final ? count($this->final) : 0; }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/Text/Diff.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.