# File lib/slack-notifier/payload_middleware/stack.rb, line 15
        def set *middlewares
          middlewares =
            if middlewares.length == 1 && middlewares.first.is_a?(Hash)
              middlewares.first
            else
              middlewares.flatten
            end

          @stack = middlewares.map do |key, opts|
            PayloadMiddleware.registry.fetch(key).new(*[notifier, opts].compact)
          end
        end