wp-includes/Requests/src/Proxy/Http.php:98Register the necessary callbacks
$hooksWpOrg\Requests\Hooks public function register(Hooks $hooks) { $hooks->register('curl.before_send', [$this, 'curl_before_send']); $hooks->register('fsockopen.remote_socket', [$this, 'fsockopen_remote_socket']); $hooks->register('fsockopen.remote_host_path', [$this, 'fsockopen_remote_host_path']); if ($this->use_authentication) { $hooks->register('fsockopen.after_headers', [$this, 'fsockopen_header']); } }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.