isSystemMail example

->get($orderStatus->getName());
                }
                $orderNodes['data'][] = $node;
            } elseif ($mail->isPaymentStateMail()) {
                $paymentStatus = $mail->getStatus();
                if ($paymentStatus !== null) {
                    $node['name'] = $this->get('snippets')
                        ->getNamespace('backend/static/payment_status')
                        ->get($paymentStatus->getName());
                }
                $paymentNodes['data'][] = $node;
            } elseif ($mail->isSystemMail()) {
                $systemNodes['data'][] = $node;
            } elseif ($mail->isUserMail()) {
                $node['checked'] = false;
                $userNodes['data'][] = $node;
            } elseif ($mail->isDocumentMail()) {
                $node['name'] = $this->getFriendlyNameOfDocumentEmail($node['name']);
                $documentNodes['data'][] = $node;
            }
        }

        $statusNodes['data'][] = $paymentNodes;