src/UniqueSluggifier.php
public function slugify($text)
    {
        $slugged = $this->slugify->slugify($text);

        $count = 1;
        $orig = $slugged;
        while (in_array($slugged, $this->used)) {
            $slugged = $orig . '-' . $count;
            $count++;
        }

        $this->used[] = $slugged;
        return $slugged;
    }
public function slugify($text)
    {
        $slugged = $this->slugify->slugify($text);

        $count = 1;
        $orig = $slugged;
        while (in_array($slugged, $this->used)) {
            $slugged = $orig . '-' . $count;
            $count++;
        }

        $this->used[] = $slugged;
        return $slugged;
    }
Slugify

@param string $text
@return string