# File lib/grape/middleware/stack.rb, line 87
      def build(builder = Rack::Builder.new)
        others.shift(others.size).each(&method(:merge_with))
        middlewares.each do |m|
          m.block ? builder.use(m.klass, *m.args, &m.block) : builder.use(m.klass, *m.args)
        end
        builder
      end