wp-includes/SimplePie/src/Category.php:115String-ified version
string public function __toString() { // There is no $this->data here return md5(serialize($this)); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/SimplePie/src/Category.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.