module ActionDispatch::Routing::Mapper::Resources

def nested
  unless resource_scope?
    raise ArgumentError, "can't use nested outside resource(s) scope"
  end
  with_scope_level(:nested) do
    if shallow?
      with_exclusive_scope do
        if @scope[:shallow_path].blank?
          scope(parent_resource.nested_scope, nested_options) { yield }
        else
          scope(@scope[:shallow_path], :as => @scope[:shallow_prefix]) do
            scope(parent_resource.nested_scope, nested_options) { yield }
          end
        end
      end
    else
      scope(parent_resource.nested_scope, nested_options) { yield }
    end
  end
end