protected function contains(array $attributes = array())
    {
        $collection = $this->findAll();
        $filtered   = $collection->filter(function($value, $key) use($attributes) {
            foreach ($attributes as $keyname => $attrVal) {
                if ($value->{$keyname} != $attrVal) {
                    return false;
                }
            }
            return true;
        });
        return $filtered->count() > 0;
    }