get_aliased_arg (OpenID::Message)

    # File lib/openid/message.rb, line 411
        def get_aliased_arg(aliased_key, default=nil)
          if aliased_key == 'ns'
            return get_openid_namespace()
          end

          ns_alias, key = aliased_key.split('.', 2)
          if ns_alias == 'ns'
            uri = @namespaces.get_namespace_uri(key)
            if uri.nil? and default == NO_DEFAULT
              raise KeyNotFound, "Namespace #{key} not defined when looking "\
                                 "for #{aliased_key}"
            else
              return (uri.nil? ? default : uri)
            end
          end

          if key.nil?
            key = aliased_key
            ns = nil
          else
            ns = @namespaces.get_namespace_uri(ns_alias)
          end

          if ns.nil?
            key = aliased_key
            ns = get_openid_namespace
          end

          return get_arg(ns, key, default)
        end