class ActionDispatch::Routing::Mapper::Mapping

def normalize_defaults!
  @defaults.merge!(scope[:defaults]) if scope[:defaults]
  @defaults.merge!(options[:defaults]) if options[:defaults]
  options.each do |key, default|
    unless Regexp === default || IGNORE_OPTIONS.include?(key)
      @defaults[key] = default
    end
  end
  if options[:constraints].is_a?(Hash)
    options[:constraints].each do |key, default|
      if URL_OPTIONS.include?(key) && (String === default || Fixnum === default)
        @defaults[key] ||= default
      end
    end
  end
  if Regexp === options[:format]
    @defaults[:format] = nil
  elsif String === options[:format]
    @defaults[:format] = options[:format]
  end
end