build_handle

# File activesupport/lib/active_support/notifications/fanout.rb, line 286
      def build_handle(name, id, payload)
        groups = groups_for(name).map do |group_klass, grouped_listeners|
          group_klass.new(grouped_listeners, name, id, payload)
        end

        if groups.empty?
          NullHandle
        else
          Handle.new(self, name, id, groups, payload)
        end
      end