def attachment_attributes_valid?
        [:size, :content_type].each do |attr_name|
          enum = attachment_options[attr_name]
          errors.add attr_name, I18n.translate("activerecord.errors.messages.inclusion", attr_name => enum) unless enum.nil? || enum.include?(send(attr_name))
        end
      end
def attachment_attributes_valid?
        [:size, :content_type].each do |attr_name|
          enum = attachment_options[attr_name]
          errors.add attr_name, I18n.translate("activerecord.errors.messages.inclusion", attr_name => enum) unless enum.nil? || enum.include?(send(attr_name))
        end
      end
validates the size and content_type attributes according to the current model's options