How to add named_route programmatically

route_options = {:controller => 'toys', :action => 'index', :owner_id => 'toy_owner'}

# initialize Mapper with the current RouteSet
mapper = ActionController::Routing::RouteSet::Mapper.new(ActionController::Routing::Routes)

# create a new named_route
new_named_route = mapper.named_route('rubber_duck', 'rubber_duck', route_options)

# add to current RouteSet
ActionController::Routing::Routes.routes.insert(0, new_named_route)