public function addSerialNumber($number, $isMain = false)
    {
        $numberBranch['kod'] = $number;
        $crrentSerialNumbers = $this->getDataValue('vyrobniCislaPrijata');
        if ($isMain) {
            if (!empty($crrentSerialNumbers)) {
                foreach (array_keys($crrentSerialNumbers) as $serialNumberID) {
                    unset($this->data['vyrobniCislaPrijata'][$serialNumberID]['vyrobnicislohlav']);
                }
            }
            $numberBranch['vyrobnicislohlav'] = 1;
        }
        $this->setDataValue('mnozMj', count($crrentSerialNumbers) + 1);
        return $this->addArrayToBranch($numberBranch, 'vyrobniCislaPrijata');
    }