Neos\Neos\Ui\Controller\BackendServiceController::flowQueryAction PHP Method

    public function flowQueryAction(array $chain)
    {
        $createContext = array_shift($chain);
        $finisher = array_pop($chain);
        $flowQuery = new FlowQuery(array_map(function ($envelope) {
            return $this->nodeService->getNodeFromContextPath($envelope['$node']);
        }, $createContext['payload']));
        foreach ($chain as $operation) {
            $flowQuery = call_user_func_array([$flowQuery, strtolower($operation['type'])], $operation['payload']);
        }
        if ('GET' === $finisher['type']) {
            $result = $flowQuery->get();
        }
        $nodeInfoHelper = new NodeInfoHelper();
        return json_encode($nodeInfoHelper->renderNodes($result, $this->getControllerContext()));
    }