public function validateUniqueness($entity, $parameters)
    {
        $errors = new Collection();

        foreach ($this->getManager()->getUnique() as $name => $attributes) {
            // Check if attribute exists...

            $q = $this->getManager()->getRepository()->getQuery();

            $where = collect();
            foreach ($attributes as $attribute) {
                $attribute = explode(':', $attribute);

                $col = count($attribute) > 1 ? $attribute[1] : $attribute[0];
                $attribute = $attribute[0];

                $value = $parameters->get($attribute, $entity->$attribute);

                if ($value) {
                    $where[$col] = is_object($value) && $value instanceof EntityContract ? $value->id : $value;
                }
            }

            if ($entity->exists) {
                $q->where('id', '!=', $entity->id);
            }

            if ($where->count() > 0 && $q->where($where->toArray())->count() > 0) {
                $exception = $this->getManager()->getException(Tokens::NOT_UNIQUE);

                $errors->push(new $exception($where));
            }
        }

        return $errors;
    }