public function setMatchMin($matchMin)
    {
        if (is_int($matchMin) === true && $matchMin >= 0) {
            $this->matchMin = $matchMin;
        } else {
            $msg = "The 'matchMin' argument must be a positive integer, '" . gettype($matchMin) . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }