Cviebrock\EloquentSluggable\SluggableScopeHelpers::getSlugKeyName PHP Method

    public function getSlugKeyName()
    {
        if (property_exists($this, 'slugKeyName')) {
            return $this->slugKeyName;
        }
        $config = $this->sluggable();
        $name = reset($config);
        $key = key($config);
        // check for short configuration
        if ($key === 0) {
            return $name;
        }
        return $key;
    }