yii\web\Response::sendHeaders PHP Метод

    protected function sendHeaders()
    {
        if (headers_sent()) {
            return;
        }
        if ($this->_headers) {
            $headers = $this->getHeaders();
            foreach ($headers as $name => $values) {
                $name = str_replace(' ', '-', ucwords(str_replace('-', ' ', $name)));
                // set replace for first occurrence of header but false afterwards to allow multiple
                $replace = true;
                foreach ($values as $value) {
                    header("{$name}: {$value}", $replace);
                    $replace = false;
                }
            }
        }
        $statusCode = $this->getStatusCode();
        header("HTTP/{$this->version} {$statusCode} {$this->statusText}");
        $this->sendCookies();
    }