wp-includes/SimplePie/src/Parse/Date.php:664Add a callback method to parse a date
$callbackcallable public function add_callback($callback) { if (is_callable($callback)) { $this->user[] = $callback; } else { trigger_error('User-supplied function must be a valid callback', E_USER_WARNING); } }One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
none to void.verified against sourcesrc/wp-includes/SimplePie/src/Parse/Date.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.