changed_values

# File activemodel/lib/active_model/attribute_mutation_tracker.rb, line 18
    def changed_values
      attr_names.each_with_object(ActiveSupport::HashWithIndifferentAccess.new) do |attr_name, result|
        if changed?(attr_name)
          result.store(attr_name, original_value(attr_name), convert_value: false)
        end
      end
    end