def url
      return unless self.asset
      return self.asset.url unless persisted?
      self.asset.url(ei: Base64.urlsafe_encode64(self.id.to_s))
    end
def url
      return unless self.asset
      return self.asset.url unless persisted?
      self.asset.url(ei: Base64.urlsafe_encode64(self.id.to_s))
    end
@!attribute embeddable_type
   @return [String, nil] The type of the #embeddable association
 @!attribute embeddable_id
   @return [String, Integer, nil] The uuid (or id) of the #embeddable association
 @!attribute asset_uid
   @return [String, nil] The unique id of the Dragonfly #asset
 @!attribute asset_name
   @return [String, nil] The name of the Dragonfly #asset
 Dragonfly url for the asset.

 @return [String] the url for the dragonfly asset