LMongo\Eloquent\Relations\BelongsToMany::buildDictionary PHP Method

    protected function buildDictionary(Collection $results)
    {
        $dictionary = array();
        // First we will create a dictionary of models keyed by the foreign key of the
        // relationship as this will allow us to quickly access all of the related
        // models without having to do nested looping which will be quite slow.
        foreach ($results as $result) {
            foreach ($result->{$this->foreignKey} as $key) {
                $dictionary[(string) $key][] = $result;
            }
        }
        return $dictionary;
    }