Neos\ContentRepository\Eel\FlowQueryOperations\FindOperation::hasOnlyInstanceOfFilters PHP Method

    protected function hasOnlyInstanceOfFilters(array $filters)
    {
        foreach ($filters as $filter) {
            if (!isset($filter['AttributeFilters']) || count($filter['AttributeFilters']) !== 1 || $filter['AttributeFilters'][0]['Operator'] !== 'instanceof') {
                return false;
            }
        }
        return true;
    }