inherited_with_inheritable_attributes

# File activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb, line 128
    def inherited_with_inheritable_attributes(child)
      inherited_without_inheritable_attributes(child) if respond_to?(:inherited_without_inheritable_attributes)

      if inheritable_attributes.equal?(EMPTY_INHERITABLE_ATTRIBUTES)
        new_inheritable_attributes = EMPTY_INHERITABLE_ATTRIBUTES
      else
        new_inheritable_attributes = inheritable_attributes.inject({}) do |memo, (key, value)|
          memo.update(key => value.duplicable? ? value.dup : value)
        end
      end

      child.instance_variable_set('@inheritable_attributes', new_inheritable_attributes)
    end