public function setDateRegister($dateRegister)
    {
        $dateRegister = ($dateRegister === null ? $dateRegister : (string) $dateRegister);

        if ($this->exists() && $this->dateRegister !== $dateRegister) {
            $this->updated['dateRegister'] = true;
        }

        $this->dateRegister = $dateRegister;

        return $this;
    }