module Roda::RodaPlugins::Middleware::ClassMethods

def new(app)

Create a Forwarder instead of a new instance. 
def new(app)
  Forwarder.new(self, app)
end

def route(&block)

that the next middleware is called.
Override the route block so that if no route matches, we throw so 
def route(&block)
  super do |r|
    instance_exec(r, &block)
    throw :next, true
  end
end