protected function runSerializeTransformsOnCollection(Collection $collection)
    {
        // Loop through the collection and transform each model
        return $collection->map(function ($item) {

            // If collection item isn't a model, don't do anything
            if (!is_a($item, Model::class)) return $item;

            // Serialize the model
            return $this->runSerializeTransformsOnModel($item);

        // Remove all the models whose transforms did not return a value. Then
        // convert back to an array.
        })->filter()->all();
    }