wp-includes/Requests/src/Response.php:109Is the response a redirect?
boolean public function is_redirect() { $code = $this->status_code; return in_array($code, [300, 301, 302, 303, 307], true) || $code > 307 && $code < 400; }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/Requests/src/Response.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.