class ActionDispatch::Routing::RouteSet::NamedRouteCollection

def add_url_helper(name, defaults, &block)
  helper = CustomUrlHelper.new(name, defaults, &block)
  path_name = :"#{name}_path"
  url_name = :"#{name}_url"
  @path_helpers_module.module_eval do
    redefine_method(path_name) do |*args|
      helper.call(self, args, true)
    end
  end
  @url_helpers_module.module_eval do
    redefine_method(url_name) do |*args|
      helper.call(self, args, false)
    end
  end
  @path_helpers << path_name
  @url_helpers << url_name
  self
end