def readonly_attributes(*attrs)
      @readonly_attributes ||= [:created_at, :updated_at, :completed_at]
      if attrs.any?
        @readonly_attributes.map!(&:to_sym).concat(attrs).uniq!
        setup_attributes(@readonly_attributes, true)
      end
      @readonly_attributes
    end
def readonly_attributes(*attrs)
      @readonly_attributes ||= [:created_at, :updated_at, :completed_at]
      if attrs.any?
        @readonly_attributes.map!(&:to_sym).concat(attrs).uniq!
        setup_attributes(@readonly_attributes, true)
      end
      @readonly_attributes
    end
Readonly attributes don't get POSTed.
 (timestamps are included by default)