Neos\Eel\FlowQuery\Operations\IsOperation::evaluate PHP Метод

    public function evaluate(FlowQuery $flowQuery, array $arguments)
    {
        if (count($arguments) == 0) {
            return count($flowQuery->getContext()) > 0;
        } else {
            $flowQuery->pushOperation('is', []);
            $flowQuery->pushOperation('filter', $arguments);
        }
    }