def attribute_change(attr)
      attr = database_field_name(attr)
      [changed_attributes[attr], attributes[attr]] if attribute_changed?(attr)
    end
def attribute_change(attr)
      attr = database_field_name(attr)
      [changed_attributes[attr], attributes[attr]] if attribute_changed?(attr)
    end
Get the old and new value for the provided attribute.

 @example Get the attribute change.
   model.attribute_change("name")

 @param [ String ] attr The name of the attribute.

 @return [ Array<Object> ] The old and new values.

 @since 2.1.0