attributes are set at the end

default_value_for

def initialize_with_defaults(attrs = nil)
  initialize_without_defaults() do
    if attrs
      stringified_attrs = attrs.stringify_keys
      safe_attrs = sanitize_for_mass_assignment(stringified_attrs)
      safe_attribute_names = safe_attrs.keys.map do |x|
        x.to_s
      end
    end
    self.class._default_attribute_values.each do |attribute, container|
      if safe_attribute_names.nil? || safe_attribute_names.none? { |attr_name| attr_name =~ /^#{attribute}($|\()/ }
        __send__("#{attribute}=", container.evaluate(self))
        changed_attributes.delete(attribute)
      end
    end
    yield(self) if block_given?
  end
  self.attributes= attrs
  self
end