private function parseIterator(Iterator $iterator)
    {
        $iterator = $this->parseHeaderRow($iterator);
        if ($this->csvFormat->getDataStart() > 1 || $this->csvFormat->getLimit() !== -1) {
            $iterator = new LimitIterator(
                $iterator,
                max(0, $this->csvFormat->getDataStart() - 1),
                $this->csvFormat->getLimit()
            );
        }
        return $iterator;
    }