Notify::fetchSimple

private function fetchSimple(int $offset): array
{
	$simpleCollection = [];
	$nextPageIsSimple = $this->lastType === self::SIMPLE_TYPE;
	$needMoreOnFirstPage = $this->firstPage && $offset < $this->pageLimit;
	$notEnoughFromPreviousStep = $this->lastType === self::CONFIRM_TYPE && $offset < $this->pageLimit;

	if ($needMoreOnFirstPage || $notEnoughFromPreviousStep || $nextPageIsSimple)
	{
		$simpleCollection = $this->requestData(self::SIMPLE_TYPE, $this->pageLimit - $offset);
	}

	return $simpleCollection;
}