wp-includes/Requests/src/Proxy/Http.php:161Get the authentication string (user:pass)
string public function get_auth_string() { return $this->user . ':' . $this->pass; }Introduced in 1.6. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/Requests/src/Proxy/Http.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.