/**
* @param string $userAgent
* @param int $tolerance
*
* @return null|string
*/
public function getDeviceIDFromRIS($userAgent, $tolerance)
{
if ($tolerance === null) {
return WurflConstants::NO_MATCH;
}
$match = Utils::risMatch($this->userAgents, $userAgent, $tolerance);
if (!empty($match)) {
return $this->userAgentsWithDeviceID[$match];
}
return WurflConstants::NO_MATCH;
}