changes

# File activerecord/lib/active_record/attribute_mutation_tracker.rb, line 15
    def changes
      attr_names.each_with_object({}.with_indifferent_access) do |attr_name, result|
        if changed?(attr_name)
          result[attr_name] = [attributes[attr_name].original_value, attributes.fetch_value(attr_name)]
        end
      end
    end