new

# File actionpack/lib/action_dispatch/routing/mapper.rb, line 1162
          def initialize(entities, api_only, shallow, options = {})
            if options[:param].to_s.include?(":")
              raise ArgumentError, ":param option can't contain colons"
            end

            @name       = entities.to_s
            @path       = (options[:path] || @name).to_s
            @controller = (options[:controller] || @name).to_s
            @as         = options[:as]
            @param      = (options[:param] || :id).to_sym
            @options    = options
            @shallow    = shallow
            @api_only   = api_only
            @only       = options.delete :only
            @except     = options.delete :except
          end