yii\httpclient\Request::toString PHP Method

    public function toString()
    {
        if (!$this->isPrepared) {
            $this->prepare();
        }
        $result = strtoupper($this->getMethod()) . ' ' . $this->getFullUrl();
        $parentResult = parent::toString();
        if ($parentResult !== '') {
            $result .= "\n" . $parentResult;
        }
        return $result;
    }