public function getByCollectionName(string $collectionName) : DbCollection
 {
     return $this->model->where('collection_name', $collectionName)->get();
 }
 /**
  * Get all media for the given type.
  *
  * @param string $modelType
  *
  * @return \Illuminate\Database\Eloquent\Collection
  */
 public function getByModelType($modelType)
 {
     return $this->model->where('model_type', $modelType)->get();
 }