code: public function timestamp(bool $onUpdate = false): self
  	{
  		$this->type = 'timestamp';
  		$this->default = 'NOT null DEFAULT CURRENT_TIMESTAMP' . ($onUpdate ? ' ON UPDATE CURRENT_TIMESTAMP' : '');
  		$this->setDefault('CURRENT_TIMESTAMP');
  		return $this;
  	}
docs: Nastavi typ na timestamp (pri vytvoreni se ulozi datum)
  @param bool $onUpdate true = datum se zmeni pri zmene
  @return self