# File lib/active_model/errors.rb, line 226
    def add_on_empty(attributes, options = {})
      [attributes].flatten.each do |attribute|
        value = @base.send(:read_attribute_for_validation, attribute)
        is_empty = value.respond_to?(:empty?) ? value.empty? : false
        add(attribute, :empty, options) if value.nil? || is_empty
      end
    end