def add(resource)
      if @list.key? resource.route
        raise DuplicateResource, "A resource accessible via #{resource.http_verb} #{resource.url} already exists"
      end
      @list[resource.route] = resource
    end
def add(resource)
      if @list.key? resource.route
        raise DuplicateResource, "A resource accessible via #{resource.http_verb} #{resource.url} already exists"
      end
      @list[resource.route] = resource
    end
Add a resource to the list

 @param [Kanpachi::Resource] The resource to add.
 @return [Hash<Kanpachi::Resource>] All the added resources.
 @raise DuplicateResource If a resource is being duplicated.
 @api public