/**
* HOTP constructor.
*
* @param string $label
* @param string|null $secret
* @param int $counter
* @param string $digest
* @param int $digits
*/
public function __construct($label, $secret = null, $counter = 0, $digest = 'sha1', $digits = 6)
{
parent::__construct($label, $secret, $digest, $digits);
$this->setCounter($counter);
}