public function iShouldGetValidUuid()
{
preg_match('/^([a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12})$/', $this->output, $matches);
if (empty($matches) && $this->output != '11111111-1111-1111-1111-111111111111') {
throw new \Exception($this->output . ' is not a valid UUID.');
}
return true;
}